C8.1· 76 questions · 193 marks · 232 min · 2004–2025· Structured questions
Every Cambridge IGCSE Mathematics Paper 1 question on introduction to probability, laid out as 35 A4 pages with the mark scheme below. Nothing is left out. Free to read, no account.


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![Question 40: Ethan has a box of toys. He takes a toy at random. Toy Car Train Bus Other Probability 0.2 0.45 0.08 Complete the table. [2]](https://img.pastlit.com/crops/f1c89ef6-ab76-4684-bf44-d855e65dcd42/q15.webp)
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35 / 35Answers below. Sit the paper first if you are practising.
Pastlit
Mathematics 0580 · Introduction to probability — Paper 1
IGCSE · topical answer key — answer key (teacher use)
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| 1 | see sheet | 4 | 0580/11 Oct/Nov 2004 |
| 2 | see sheet | 1 | 0580/11 May/June 2005 |
| 3 | see sheet | 3 | 0580/11 May/June 2006 |
| 4 | see sheet | 5 | 0580/11 Oct/Nov 2006 |
| 5 | see sheet | 4 | 0580/11 Oct/Nov 2008 |
| 6 | see sheet | 2 | 0580/11 May/June 2010 |
| 7 | see sheet | 4 | 0580/11 Oct/Nov 2010 |
| 8 | see sheet | 3 | 0580/12 Oct/Nov 2010 |
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| 10 | see sheet | 2 | 0580/12 May/June 2011 |
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| 13 | see sheet | 5 | 0580/13 May/June 2012 |
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| 21 | see sheet | 2 | 0580/12 Feb/March 2015 |
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| 45 | see sheet | 2 | 0580/11 Oct/Nov 2019 |
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| 48 | see sheet | 3 | 0580/12 Feb/March 2020 |
| 49 | see sheet | 2 | 0580/13 May/June 2020 |
| 50 | see sheet | 1 | 0580/12 Oct/Nov 2020 |
| 51 | see sheet | 2 | 0580/13 Oct/Nov 2020 |
| 52 | see sheet | 1 | 0580/11 May/June 2021 |
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| 54 | see sheet | 2 | 0580/13 May/June 2021 |
| 55 | see sheet | 4 | 0580/12 Oct/Nov 2021 |
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| 57 | see sheet | 1 | 0580/13 Oct/Nov 2021 |
| 58 | see sheet | 2 | 0580/11 May/June 2022 |
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| 60 | see sheet | 3 | 0580/11 Oct/Nov 2022 |
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| 68 | see sheet | 3 | 0580/12 Feb/March 2024 |
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| 70 | see sheet | 1 | 0580/13 May/June 2024 |
| 71 | see sheet | 3 | 0580/13 Oct/Nov 2024 |
| 72 | see sheet | 5 | 0580/12 Feb/March 2025 |
| 73 | see sheet | 4 | 0580/11 Oct/Nov 2025 |
| 74 | see sheet | 3 | 0580/12 Oct/Nov 2025 |
| 75 | see sheet | 1 | 0580/12 Oct/Nov 2025 |
| 76 | see sheet | 4 | 0580/13 Oct/Nov 2025 |
20 Aminata has a bag containing 35 beads. The beads are either blue, yellow or red. One bead is chosen at random. 2 3 The probability of choosing a blue bead is and the probability of choosing a yellow bead is . 7 5 Calculate (a) the number of blue beads in the bag, Answer(a) [2] (b) the probability of choosing a red bead. Answer(b) [2]
4 marks
Mark scheme: 20 (a) 10 2 2 M1 for x 35 7 2 4 2 3 (b) oe or 0.114 (...) + M1 for 1 - soi or 35 7 5 or 11.4% 3 [35 - (his (a) + x 35] ÷ 35 5 0.11 or 11% seen imply M1
2 A bag of 30 sweets contains 8 chocolates, 13 nougats and 9 toffees. A sweet is selected at random. What is the probability that it is a toffee? Answer [1]
1 marks
Mark scheme: 2 9 3 1 isw only for incorrect cancelling or or 0.3 or 30% isw 30 10
9 (a) A bowl of fruit contains 3 apples, 4 bananas, 2 pears and 1 orange. Aminata chooses one piece of fruit at random. What is the probability that she chooses (i) a banana, Answer(a)(i) [1] (ii) a mango? Answer(a)(ii) [1] 5 (b) The probability that it will rain in Switzerland on 1st September is . 12 State the probability that it will not rain in Switzerland on 1st September. Answer(b) [1]
3 marks
Mark scheme: 9 (a) (i) 4 1 oe. 10 (ii) 0 1 (b) 7 1 o.e. 12 5
23 The diagram shows a six-sided spinner. For Examiner's Use 6 1 5 2 4 3 5 (a) Amy spins a biased spinner and the probability she gets a two is . 36 Find the probability she (i) does not get a two, Answer(a) (i) [1] (ii) gets a seven, Answer(a) (ii) [1] (iii) gets a number on the spinner less than 7. Answer(a) (iii) [1] (b) Joel spins his blue spinner 99 times and gets a two 17 times. Write down the relative frequency of getting a two with Joel’s spinner. Answer(b) [1] 21 (c) The relative frequency of getting a two with Piero’s spinner is . 102 Which of the three spinners, Amy’s, Joel’s or Piero’s, is most likely to give a two? Answer(c) [1]
5 marks
Mark scheme: 23 (a) (i) 3631 oe isw 1 Fraction, decimal or percentage only. (ii) 0 Final ans 1 06 , 360 , 0% or zero. Not allow ‘no’, none, 70 or 0/0. (iii) 1 1 Allow 66 or 3636 or 100%. (b) 1799 isw 1 If decimal, allow art 0.172 (c) Piero’s 1 Can be indicated by 10221 5 Total for the paper is 56 marks
20 (a) 85% of the seeds in a packet will produce red flowers. For One seed is chosen at random. Examiner's Use What is the probability that it will not produce a red flower? Answer(a) [1] (b) A box of 15 pencils contains 5 red, 4 yellow and 6 blue pencils. One pencil is chosen at random from the box. Find the probability that it is (i) yellow, Answer(b)(i) [1] (ii) yellow or blue, Answer(b)(ii) [1] (iii) green. Answer(b)(iii) [1]
4 marks
Mark scheme: 20 (a) 15(%) or 0.15 or 10015 oe 1 isw for change of form or cancelling only in all 4 parts. Not ratio. (b) (i) oe cao 1 Allow 0.267 or 0.266(6….) or % form 15 Minimum 3 significant figures 10 (ii) oe cao 1 Allow 0.667 or 0.666(6…) or % form 15 Minimum 3 significant figures Consistent use of wrong denominator in all of (b), −1 once. 0 (iii) 0 or cao 1 Allow nil, none or zero only. No other 15 denominator allowed.
3 In a group of 35 students, 14 go to school by bus. Write down the probability that a student, chosen at random, does not go to school by bus. Give your answer as a fraction in its lowest terms. Answer [2]
2 marks
Mark scheme: 3 21 3 2 W1 for 5 35 14 M1 1 − oe 35 2 SC1 answer 5
17 Simon has ten cards, numbered 1 to 10. He chooses a card at random. Write down the probability that the number on the card is (a) 8, Answer(a) [1] (b) 12, Answer(b) [1] (c) an odd number, Answer(c) [1] (d) not a multiple of 3. Answer(d) [1]
4 marks
Mark scheme: 117 (a) 1 10 0 (b) 0 1 Accept but no other number than 10 10 5 (c) oe 1 10 7 (d) 1 10
10 The heights of 43 children are measured to the nearest centimetre. For Braima draws a bar chart from this information. Examiner's Use 16 14 12 10 Frequency 8 6 4 2 0 120-129 130-139 140-149 150-159 160-169 170-179 180-189 Height (centimetres) A child is chosen at random. Write down, as a fraction, the probability that the child will be (a) in the group 140 – 149 cm, Answer(a) [1] (b) less than 160 cm, Answer(b) [1] (c) in the group 160 – 169 cm. Answer(c) [1]
3 marks
Mark scheme: 15 10 (a) cao final answer 1 If zero in (a) and (b) then 43 SC1 if both (a) and (b) are correct decimals or percentages as answers. (Mark as 0 for (a) and SC1 for (b)) 42 (b) cao final answer 1 43 0 (c) 0 or 1 43
20 4 4 5 6 8 (a) The diagram shows 5 discs. One disc is chosen at random. (i) Which number is most likely to be chosen? Answer(a)(i) [1] (ii) What is the probability that the number on the disc is even? Answer(a)(ii) [1] (iii) What is the probability that the number on the disc is even and a factor of 20? Answer(a)(iii) [1] (b) A disc is chosen at random from the discs with even numbers. What is the probability that the number on the disc is a factor of 20? Answer(b) [1] Questions 21 and 22 are printed on the next page
4 marks
Mark scheme: 20 (a) (i) 4 1 4 (ii) oe 1 5 2 (iii) oe 1 5 2 (b) oe 1 4
3 A letter is chosen at random from the following word. S T A T I S T I C S Write down the probability that the letter is (a) A or I , Answer(a) [1] (b) E. Answer(b) [1]
2 marks
Mark scheme: 3 3 1 (a) or 0.3 or 30% 10 1 0 (b) 0 or or 0% 10
20 In a survey of 60 cars, the type of fuel that they use is recorded in the table below. For Examiner's Each car only uses one type of fuel. Use Petrol Diesel Liquid Hydrogen Electricity 40 12 2 6 (a) Write down the mode. Answer(a) [1] (b) Olav drew a pie chart to illustrate these figures. Calculate the angle of the sector for Diesel. Answer(b) [2] (c) Calculate the probability that a car chosen at random uses Electricity. Write your answer as a fraction in its simplest form. Answer(c) [2]
5 marks
Mark scheme: 20 (a) Petrol cao 1 (b) 72 2 M1 for 360 × 12 ÷ 60 1 6 3 2 (c) 2 B1 or or or 0.1 or 10% 10 60 30 20
5 For 1 During April the probability that it will rain on any one day is . Examiner's 6 Use On how many of the 30 days in April would it be expected to rain? Answer [1]
1 marks
Mark scheme: Qu. Answers Mark Part Marks 1 25 1
20 (a) Colin has some seeds. For The probability a seed will grow is 0.85 . Examiner's Use Find the probability that a seed will not grow. Answer(a) [1] (b) Richard grows flowers. Some of his flowers are chosen at random. The colours are recorded in the table below. Colour of Relative Frequency flower Frequency Red 20 0.16 Blue 15 Yellow 35 Other 55 (i) Complete the table to show the relative frequency of each colour. [2] (ii) Richard grows 800 flowers in total. Estimate how many of these flowers are red. Answer(b)(ii) [2]
5 marks
Mark scheme: 20 (a) [0].15 oe 1 (b) (i) 0.12, 0.28, 0.44 oe 2 M1 for division of 15, 35 or 55 by their 125 Or B1 for 1 correct (ii) 128 2 M1 for 800 × [0].16
5 A bowl of fruit contains only 8 peaches, 5 oranges and 6 apples. For One piece of fruit is chosen at random. Examiner's Use Write down the probability that it is (a) an orange, Answer(a) [1] (b) not a peach. Answer(b) [1]
2 marks
Mark scheme: 5 5 (a) oe 1 0.263 19 11 1 0.579 or 0.5789 (b) oe 19
12 The probability of Sachin’s team winning any match is 0.45. (a) Write down the probability of Sachin’s team not winning any match. Answer(a) … [1] (b) In a season there are 40 matches. How many matches should Sachin’s team expect to win in a season? Answer(b) … [2] _____________________________________________________________________________________
3 marks
Mark scheme: 12 (a) [0].55 oe 1 (b) 18 2 M1 for 40 × [0].45 oe IGCSE – May/June 2013 0580 11
20 Marco throws a six-sided dice 27 times. For Examiner's The bar chart shows his results. Use 8 7 6 5 Frequency 4 3 2 1 0 1 2 3 4 5 6 Score on dice (a) Write down the mode. Answer(a) … [1] (b) Work out the probability that Marco throws a number less than 5. Answer(b) … [2] (c) Calculate the mean. Answer(c) … [3]
6 marks
Mark scheme: 20 (a) 4 cao 1 (b) 21 2 M1 for 3 + 6 + 5 + 7 + 4 or 21 seen 27 oe isw (c) 3.33(3…) 3 M1 for 3 × 1 + 6 × 2 + 5 × 3 + 7 × 4 + 4 × 5 + 2 × 6, allow one incorrect product or 90 seen and M1 dep for ‘their 90’ ÷ 27
9 The probability that the school hockey team will win its next match is 0.45 . The probability that it will lose its next match is 0.3 . Work out the probability that the school hockey team will draw its next match. Answer … [2] _____________________________________________________________________________________
2 marks
Mark scheme: 9 0.25 oe 2 M1 for 1– (0.45 + 0.3) or better or SC1 for 0.52 as final answer 24
14 S P A C E S One of the 6 letters is taken at random. (a) Write down the probability that the letter is S. Answer(a) … [1] (b) The letter is replaced and again a letter is taken at random. This is repeated 600 times. How many times would you expect the letter to be S? Answer(b) … [1] _____________________________________________________________________________________
2 marks
Mark scheme: 2 14 (a) oe 1 6 (b) 200 Final answer 1FT FT 600 × their (a) providing their (a) is a probability
18 (a) The probability that FC Victoria wins the cup is 0.18 . Work out the probability that they do not win the cup. Answer(a) … [1] (b) After training, the shirts are washed. There are 5 red, 3 blue and 6 green shirts. One shirt is taken from the washing machine at random. Find the probability that it is (i) red, Answer(b)(i) … [1] (ii) blue or green, Answer(b)(ii) … [1] (iii) white. Answer(b)(iii) … [1] __________________________________________________________________________________________
4 marks
Mark scheme: 18 (a) (0).82 oe 1 5 (b) (i) oe 1 in (b) penalise consistent incorrect 14 denominator once 9 (ii) oe 1 14 (iii) 0 1 IGCSE – May/June 2014 0580 12
15 Celine buys a bag of 24 tulip bulbs. There are 8 red bulbs and 5 white bulbs. All of the other bulbs are yellow. Celine chooses a bulb at random from the bag. (a) Write down the probability that the bulb is red or white. Answer(a) … [1] (b) Write down the probability that the bulb is yellow. Answer(b) … [1] __________________________________________________________________________________________
2 marks
Mark scheme: 13 15 (a) oe 1 24 11 (b) oe 1 24 7 7 3 4
7 The probability that Raju arrives on time at school is 0.72 . (a) Write down the probability that he will not arrive on time. Answer(a) … [1] (b) Raju attends school on 200 days. Work out the expected number of days he will arrive on time. Answer(b) … [1] __________________________________________________________________________________________
2 marks
Mark scheme: 7 (a) 0.28 oe 1 (b) 144 1
15 Chico has a bag of sweets. He takes a sweet from the bag at random. The table shows the probabilities of taking each flavour of sweet. Flavour Lemon Lime Strawberry Blackcurrant Orange Probability 0.15 0.22 0.18 0.24 (a) Complete the table. [2] (b) Find the probability that the sweet is lemon or lime. Answer(b) … [1] __________________________________________________________________________________________
3 marks
Mark scheme: 15 (a) [0].21 oe 2 M1 for 1 – ([0].15 + [0].22 + [0].18 + [0].24) or 100 – (15 + 22 + 18 + 24) (b) [0].37 oe 1
16 The probability that it will rain on any day is . 5 Calculate an estimate of the number of days it will rain in a month with 30 days. Answer … [1] __________________________________________________________________________________________
1 marks
Mark scheme: 6 6 1
9 Dan either walks or cycles to school. The probability that he cycles to school is 13 . (a) Write down the probability that Dan walks to school. … [1] (b) There are 198 days in a school year. Work out the expected number of days that Dan cycles to school in a school year. … [1]
2 marks
Mark scheme: 2 9 (a) oe 1 3 (b) 66 cao 1 11 11
3 In a group of students the probability that a student is left-handed is 0.28 . A student is chosen at random from the group. Find the probability that this student is not left-handed. … [1]
1 marks
Mark scheme: 3 [0].72 oe 1
13 (a) A bag contains 16 counters. 4 of the counters are blue. A counter is taken from the bag at random. On the probability scale, draw an arrow (↓) to show the probability that this counter is blue. 0 0.5 1 [1] (b) Another bag contains 5 black counters, 8 white counters, 6 green counters and 1 yellow counter. A counter is taken from this bag at random. Find the probability that this counter is (i) white, … [1] (ii) not white. … [1]
3 marks
Mark scheme: 13 (a) Arrow 2 cm from 0 1 8 (b) (i) 1 oe 20 12 (ii) 1FT FT 1 – their (b)(i) provided their (b)(i) < 1 oe 20
17 The table shows the number of screws of different lengths in a box of 100 screws. Length (mm) 20 40 50 60 Number of screws 18 36 24 22 A screw is chosen at random from the box. Find the probability that the screw has length (a) 50 mm, … [1] (b) less than 60 mm, … [2] (c) 70 mm. … [1]
4 marks
Mark scheme: 24 17 (a) oe 1 100 78 18 + 36 + 24 22 (b) oe 2 M1 for or 1 − 100 100 100 (c) 0 1
11 E L E P H A N T Francesca chooses a letter at random from this word. (a) Write down the letter she is most likely to choose. … [1] (b) Write down the probability that she chooses the letter R. … [1]
2 marks
Mark scheme: 11 (a) E 1 (b) 0 or zero 1
4 A bag contains 20 counters. 10 counters are red, 8 are blue and the rest are yellow. One counter is taken from the bag at random. (a) Mark an arrow on the probability scale to show the probability that the counter is red. 0 1 [1] (b) Find the probability that the counter is yellow. … [1]
2 marks
Mark scheme: 4 (a) Correct arrow 1 2 (b) oe or 0.1 or 10% 1 20
15 Cups are made in a factory. The probability that one of these cups is faulty is 0.02 . (a) Find the probability that a cup is not faulty. … [1] (b) In one day 2500 cups are made. Work out the number of these cups that are expected to be faulty. … [2]
3 marks
Mark scheme: 15 (a) 0.98 oe 1 (b) 50 cao 2 M1 for 2500 × 0.02 If zero scored, SC1 for answer of 2450
16 (a) A bag contains 3 red, 5 blue and 4 green counters. A counter is picked at random. Work out the probability that the counter is (i) blue, … [1] (ii) yellow. … [1] (b) The probability of picking a brown counter from another bag is 0.35 . Work out the probability of not picking a brown counter. … [1]
3 marks
Mark scheme: 5 16 (a) (i) oe 1 12 (ii) 0 1 (b) [0].65 oe 1
15 Maria asks 50 students in her school when their birthday is. She records the information in the table. Jan to Mar Apr to Jun Jul to Sep Oct to Dec Number of birthdays 9 21 14 6 (a) Find the relative frequency of a student having a birthday in April, May or June. … [1] (b) There are 750 students in the school. Estimate the number of students who have a birthday in April, May or June. … [1]
2 marks
Mark scheme: 15(a) 21 1 oe 50 15(b) 315 1FT FT their (a) × 750 provided 0 < their (a) < 1
2 The probability that Stephanie wins her next tennis match is 0.85 . Find the probability that Stephanie does not win her next tennis match. … [1]
1 marks
Mark scheme: 2 [0].15 oe 1
13 Bastian has a bag containing four types of sweet. He takes a sweet from the bag at random. Sweet Mint Fruit Toffee Chocolate Probability 0.15 0.3 0.2 Complete the table. [2]
2 marks
Mark scheme: 13 [0].35 2 M1 for 1 – (0.15 + 0.3 + 0.2)
6 A bag contains 16 counters. 3 are red, 6 are blue and the rest are yellow. Jay takes a counter from the bag at random. (a) Write down the colour Jay is most likely to take. … [1] (b) Write down the probability that the counter is red. … [1]
2 marks
Mark scheme: 6(a) Yellow 1 6(b) 3 1 or 0.1875 or 18.75% 16
17 (a) A box contains 3 blue pens, 4 red pens and 8 green pens only. A pen is chosen at random from the box. Find the probability that this pen is green. … [1] (b) A cube has only one of its six faces painted yellow. This cube is rolled 240 times. Work out the expected number of times that it lands on the yellow face. … [1]
2 marks
Mark scheme: 17(a) 8 1 oe 15 17(b) 40 1
12 The probability that Kim wins a game is 0.72 . In one year Kim will play 225 games. Work out an estimate of the number of games Kim will win. … [2]
2 marks
Mark scheme: 12 162 2 M1 for 225 × 0.72 oe
8 A bag contains 50 counters. 10 of the counters are red. One of the counters is taken from the bag at random. (a) Draw an arrow ( ) on the scale to show the probability that this counter is red. 0 0.5 1 [1] (b) Find the probability that the counter is not red. … [1]
2 marks
Mark scheme: 8(a) Arrow at 0.2 1 8(b) 0.8 oe 1
11 (a) A bag contains 6 blue counters and 2 red counters only. A counter is taken from the bag at random. Draw an arrow (↓) on the probability scale to show the probability of taking (i) a blue counter, 0 1 [1] (ii) a yellow counter. 0 1 [1] (b) Another bag contains green counters and black counters only. A counter is taken from the bag at random. The probability of taking a green counter is 0.64 . Work out the probability of taking a black counter. … [1]
3 marks
Mark scheme: 11(a)(i) 3 1 Clear indication Arrow at 4 11(a)(ii) Arrow at 0 1 Clear indication 11(b) [0].36 oe 1
15 Ethan has a box of toys. He takes a toy at random. Toy Car Train Bus Other Probability 0.2 0.45 0.08 Complete the table. [2]
2 marks
Mark scheme: 15 0.27 oe 2 M1 for 1 − (0.2 + 0.45 + 0.08) oe
2 The probability that it will be sunny tomorrow is 0.97 . Work out the probability that it will not be sunny tomorrow. … [1]
1 marks
Mark scheme: 2 [0].03 oe 1
4 A bag contains green balls and red balls only. A ball is taken at random from the bag. The probability of taking a green ball is 0.38 . Write down the probability of taking (a) a red ball, … [1] (b) a blue ball. … [1]
2 marks
Mark scheme: 4(a) [0].62 oe 1 4(b) 0 1
15 A box contains 22 coloured pencils. 6 pencils are pink, 9 pencils are blue and 7 pencils are yellow. (a) Write down the ratio pink pencils : not pink pencils. Give your answer in its simplest form. … : … [2] (b) A pencil is taken at random from the box. Write down the probability that this pencil is green. … [1]
3 marks
Mark scheme: 15(a) 3 : 8 cao 2 B1 for 6 : 16 or 8 2 3 1: or 1:2 or 1:2.67 or :1 or 0.375:1 3 3 8 If 0 scored, SC1 for 8 : 3 15(b) 0 1
6 The probability that Alex wins a prize is 0.27 . Find the probability that Alex does not win a prize. … [1]
1 marks
Mark scheme: 6 0.73 oe 1
5 Rui has a bag containing 5 black pens, 8 red pens and 3 blue pens only. He takes a pen out of the bag at random. Draw an arrow ( . ) on the probability scale to show the probability that Rui takes (a) a red pen, 0 1 [1] (b) a red pen or a blue pen. 0 1 [1]
2 marks
Mark scheme: 5(a) 1 1 Arrow at 2 5(b) 11 1 Arrow at 16
5 A bag contains 3 green balls, 4 red balls and 1 blue ball only. Matt takes a ball from the bag at random. Some probabilities are marked on the probability scale. A B C D E F G H I 0 0.5 1 Write down the letter that shows the probability that (a) Matt takes a red ball, … [1] (b) Matt does not take a blue ball. … [1]
2 marks
Mark scheme: 5(a) E cao 1 5(b) H cao 1
8 A bag contains 6 red balls and 10 blue balls only. On the probability scale, draw an arrow ( ) to show the probability that a ball taken at random is (a) blue, 0 1 1 2 [1] (b) red or blue. 0 1 1 2 [1]
2 marks
Mark scheme: 8(a) 5 1 indication at cao 8 8(b) indication at 1 cao 1
5 The diagram shows a fair 8-sided spinner. The numbers on the spinner are 3, 4, 4, 7, 7, 7, 8 and 9. (a) The spinner is spun once. Write down the probability that the spinner lands on (i) the number 7, … [1] (ii) a number greater than 2. … [1] (b) The spinner is spun 160 times. Work out the expected number of times the spinner lands on the number 7. … [1]
3 marks
Mark scheme: 5(a)(i) 3 1 oe 8 5(a)(ii) 1 1 5(b) 60 1 FT their (a)(i)
13 On any day, the probability that Marcus will get a seat on the school bus is 0.93 . (a) Write down the probability that he will not get a seat on the school bus today. … [1] (b) There are 200 school days in a year. Work out the expected number of days in a year that Marcus will not get a seat. … [1]
2 marks
Mark scheme: 13(a) 0.07 1 13(b) 14 1 FT their (a)
4 A bag contains 20 balls. 5 of these balls are red. A ball is picked at random from the bag. On the probability scale, draw an arrow ( ) to show the probability that this ball is red. 0 0.5 1 [1]
1 marks
Mark scheme: 4 Arrow at 0.25 1
16 A bag contains 7 red discs, 5 green discs and 2 pink discs. Helen takes one disc at random, records the colour and replaces it in the bag. She does this 140 times. Find how many times she expects to take a green disc. … [2]
2 marks
Mark scheme: 16 50 2 5 140 M1 for [× 140] or [×5] 7 + 5 + 2 7 + 5 + 2
7 The probability that a train is late is 0.15 . Write down the probability that the train is not late. … [1]
1 marks
Mark scheme: 7 0.85 oe 1
710 The probability that Jane wins a game is . 10 Find the probability that Jane does not win the game. … [1]
1 marks
Mark scheme: 10 3 1 oe 10
12 Francesca spins a four-sided spinner numbered 1, 2, 3 and 4. The table shows some of the probabilities of landing on each number. Number 1 2 3 4 Probability 0.18 0.21 0.37 Complete the table. [2]
2 marks
Mark scheme: 12 [0].24 2 M1 for 1 – ([0].18 + [0].21 + [0].37)
24 Yasmin has 4 white flowers, 3 red flowers and x yellow flowers. She picks a flower at random. The probability that it is white is 1. 5 Find the probability that it is yellow. … [4]
4 marks
Mark scheme: 24 13 4 B3 for [x =] 13 oe 20 or M2 for x + 3 + 4 = 4 × 5 oe or 4 × 5 – 4 – 3 1 4 or M1 for 4 × 5 or = 5 4 + 3 + x
5 Cheng spins a fair 6-sided spinner numbered 1 to 6. On the probability scale, draw an arrow ( ) to show the probability that the spinner lands on 4. 0 1 [1]
1 marks
Mark scheme: 5 Arrow at first mark 1
9 The probability that it rains tomorrow is 0.47 . Find the probability that it does not rain tomorrow. … [1]
1 marks
Mark scheme: 9 0.53 oe 1
13 A 4-sided spinner is numbered 1, 2, 3 and 4. The table shows the probability of the spinner landing on 1, 2 and 4. Number 1 2 3 4 Probability 0.27 0.18 0.32 Complete the table. [2]
2 marks
Mark scheme: 13 [0].23 oe 2 M1 for 1 − [0].27 − [0].18 − [0].32 oe
5 The probability of picking a red sweet from a bag is 0.05 . Find the probability of not picking a red sweet. … [1]
1 marks
Mark scheme: 5 0.95 oe 1
14 Mario tests new cars. The probability that a car is faulty is 0.04 . (a) Find the probability that a car is not faulty. … [1] (b) In one week Mario tests 850 cars. Find the number of cars that are expected to be faulty. … [2]
3 marks
Mark scheme: 14(a) 24 1 0.96 or 96% or final answer 25 14(b) 34 cao 2 M1 for 0.04 × 850 oe
11 A 4-faced dice is numbered 1 to 4. The table shows some of the probabilities of scoring each number. Number 1 2 3 4 Probability 0.17 0.28 0.31 Complete the table. [2]
2 marks
Mark scheme: 11 [0].24 2 M1 for 1 – 0.17 – 0.28 – 0.31oe
17 (a) = { people in a group} B = { people who own a bicycle} C = { people who own a car} There are 120 people in the group. 21 people own a bicycle. 15 people own both a bicycle and a car. 35 people do not own a bicycle and do not own a car. B C (i) Complete the Venn diagram. [2] (ii) A person from the group is chosen at random. Find the probability that this person owns a car. … [1] (b) D E Shade the region D , E . [1]
4 marks
Mark scheme: 17(a)(i) 2 B1 for two numbers in the correct places 17(a)(ii) 79 1 FT their diagram for 79 oe 120 17(b) 1
15 Eric has four colours of paint. The table shows the probability that he uses each colour. Colour Red Blue Green Yellow Probability 0.3 0.35 0.13 x Find the value of x. x = … [2]
2 marks
Mark scheme: 15 0.22 oe 2 M1 for 1 – (0.3 + 0.35 + 0.13) oe or B1 for 0.78 oe
12 A spinner is spun. The possible outcomes are A, B, C or D. The probability of spinning A, C or D is shown in the table. Letter on A B C D spinner Probability 0.2 0.05 0.35 Complete the table. [2]
2 marks
Mark scheme: 12 0.4 oe 2 M1 for 1 – (0.2 + 0.05 + 0.35) oe or B1 for 0.6 oe
21 A spinner has five sides. Each side is painted red, blue, green, yellow or orange. The table shows some of the probabilities of the spinner landing on each colour. Colour Red Blue Green Yellow Orange Probability 0.3 0.16 0.18 0.25 (a) Complete the table. [2] (b) Dan spins the spinner once. Find the probability that the spinner lands on red or blue. … [2]
4 marks
Mark scheme: 21(a) 0.11 oe 2 M1 for 1 – (0.3 + 0.16 + 0.18 + 0.25) oe or B1 for 0.89 oe 21(b) 0.46 oe 2 M1 for 0.3 + 0.16
12 Rama asks a group of students how they travel to school. The table shows the probability of how a student, chosen at random, travels to school. Bus Walk Car Other Probability 0.4 0.32 0.17 (a) Complete the table. [2] (b) There are 1800 students at the school. Find the expected number of students that walk to school. … [1]
3 marks
Mark scheme: 12(a) 0.11 oe 2 M1 for 1 – (0.4 + 0.32 + 0.17) oe 12(b) 576 1
19 (a) A bag contains these cards. 1 7 3 9 4 5 2 One of these cards is picked at random. Find the probability that the number on the card is greater than 3. … [1] (b) A box contains 3 blue cards and 7 red cards. Kim picks one card at random, notes its colour and then replaces it in the box. She then picks another card at random. (i) Complete the tree diagram. First card Second card 3 Blue 10 Blue 3 10 Red … 3 Blue 10 … Red Red … [1] (ii) Work out the probability that both of the cards Kim picks are blue. … [2]
4 marks
Mark scheme: 19(a) 4 1 oe 7 19(b)(i) 7 1 in each space on tree diagram 10 19(b)(ii) 9 2 3 3 oe M1 for oe 100 10 10
13 There are 20 cars in a car park and 3 of the cars are blue. (a) James wants to draw a pie chart to show this information. Find the angle of the sector for the blue cars in this pie chart. … [2] (b) One of the 20 cars is picked at random. Find the probability that this car is not blue.
3 marks
Mark scheme: 13(a) 54 2 3 M1 for [ 360 ] oe or 360[ 3 ] oe 20 20 13(b) 17 1 oe 20
11 Geetha has a box of toys. She picks a toy at random from the box. The probability that she picks a wooden toy is 0.6 . (a) Work out the probability that she does not pick a wooden toy. … [1] (b) The box contains three types of toys, wooden, plastic or metal. Type of toy Wooden Plastic Metal Number of toys 14 14 Probability 0.6 Complete the table. [2]
3 marks
Mark scheme: 11(a) 0.4 oe 1 11(b) 42 2 B1 for 42 0.2 0.2 B1 for 0.2 and 0.2 If B0 scored, SC1 for their two probabilities each being half of their (a)
8 In a city, the probability that it will rain today is 0.15 . Find the probability that it will not rain today in this city. … [1]
1 marks
Mark scheme: 8 0.85 oe 1
5 A bag contains 6 red balls, 4 green balls and 2 blue balls. Zia takes a ball from the bag at random. A B C D E F G 0 1 Write down the letter from the probability scale that shows the probability that (a) Zia takes a green ball … [1] (b) Zia takes a yellow ball … [1] (c) Zia does not take a blue ball. … [1]
3 marks
Mark scheme: 5(a) C 1 5(b) A 1 5(c) F 1
23 Mai buys two batteries. The probability that a battery is faulty is 1 . 10 First battery Second battery … Faulty Faulty 1 10 Not faulty … … Faulty … Not faulty Not faulty … (a) Complete the tree diagram. [2] (b) Find the probability that Mai buys two faulty batteries. … [2] (c) A shop sells 3000 batteries in one month. Work out the expected number of faulty batteries the shop sells. … [1]
5 marks
Mark scheme: 23(a) 9 1 9 1 9 2 1 1 B1 for and in correct places in 2nd 10 10 10 10 10 10 10 battery 9 or correctly placed for the first battery 10 23(b) 1 2 1 1 oe M1 for their 100 10 10 23(c) 300 1
24 % = {students in a year group} H = {students who study History} G = {students who study Geography} 80 students are in the year group. 40 students study History. % H G 10 15 (a) Complete the Venn diagram. [2] (b) Find n(G). … [1] (c) A student is chosen at random. Work out the probability that the student does not study History and does not study Geography. … [1]
4 marks
Mark scheme: 24(a) 2 B1 for one correct value correctly placed If 0 scored, SC1 for two positive integers such that n(G) = 55 24(b) 55 1 FT their 30 + their 25 provided their 30 + their 25 is less than 80 24(c) 15 1 oe 80
7 A bag contains 8 discs numbered 1 to 8. A disc is picked at random from the bag. 0 1 On the probability scale, draw an arrow ( ) to show the probability that the number is (a) an even number, label the arrow A [1] (b) 9, label the arrow B [1] (c) less than 3, label the arrow C. [1]
3 marks
Mark scheme: 7(a) Arrow labelled A on 0.5 1 7(b) Arrow labelled B on 0 1 7(c) Arrow labelled C on 0.25 1
10 A bag contains red balls and green balls. They are in the ratio red balls : green balls = 2 : 3. A ball is picked at random. Find the probability that it is a red ball. … [1]
1 marks
Mark scheme: 10 2 1 oe 5
26 There are 2 sets of traffic lights on Li’s journey to work. The probability he stops at the first set of traffic lights is 0.4 . The probability he stops at the second set of traffic lights is 0.7 . First set of traffic lights Second set of traffic lights Stops … Stops 0.4 … Does not stop Stops … … Does not stop … Does not stop (a) Complete the tree diagram. [2] (b) Work out the probability that Li does not stop at both sets of traffic lights. … [2] Question 27 is printed on the next page.
4 marks
Mark scheme: 26(a) Correct tree diagram 2 B1 for 0.6 on the first branch or 0.7 and 0.3 correct on all second branches 26(b) 0.18 oe 2 FT their tree diagram for 2 marks M1 for their 0.6 × their 0.3