Topic 17 Practice Paper: Probability — question paper
IGCSE · Cambridge IGCSE Mathematics (Extended (Core + Extended))
Topic 17 Practice Paper
Probability
READ THESE INSTRUCTIONS FIRST
- Answer all questions.
- Section A contains ten multiple-choice questions. Choose one answer, A, B, C or D, for each.
- Section B contains structured questions. Write your answers in the spaces provided.
- The number of marks is given in brackets [ ] at the end of each question or part question.
- The total mark for this paper is 30.
Original practice material written against the Cambridge IGCSE Mathematics syllabus. It is not an official Cambridge examination paper. Topic 17: the probability scale and complements, relative and expected frequency, sample space diagrams, Venn diagrams, tree diagrams with and without replacement, at-least-one complements, and conditional probability from two-way tables.
| For Examiner’s Use | |
|---|---|
| Section A | / 10 |
| Section B | / 20 |
| Total | / 30 |
Section A: Multiple-choice questions[10 marks]
Choose one answer for each question. Every correct answer scores one mark.
- 1( )
A whole number from 1 to 20 is picked at random. P(multiple of 5) is
- A¼
- B1⁄10
- C⅕
- D1⁄20
- 2( )
A coin is flipped three times. P(three tails) is
- A⅛
- B⅙
- C¼
- D⅜
- 3( )
A bag holds 6 white and 9 black counters. One is drawn. P(black) is
- A⅔
- B⅖
- C⅓
- D⅗
- 4( )
P(rain tomorrow) = 0.35. P(no rain tomorrow) is
- A0.35
- B0.65
- C0.55
- D0.75
- 5( )
A fair die is rolled 90 times. The expected number of fours is
- A10
- B12
- C15
- D18
- 6( )
Two fair coins are flipped. P(one head and one tail) is
- A½
- B¼
- C⅓
- D¾
- 7( )
A spinner wins each go with probability 0.2. In two independent goes, P(win both) is
- A0.4
- B0.2
- C0.08
- D0.04
- 8( )
A bag holds 3 red and 5 green counters. Two are drawn with replacement. P(both green) is
- A9⁄64
- B25⁄64
- C5⁄14
- D15⁄64
- 9( )
A darts player hits the bullseye with probability 0.7. In two throws, P(exactly one bullseye) is
- A0.49
- B0.21
- C0.42
- D0.91
- 10( )
Two events: the chance of A is 0.6, the chance of B is 0.5, and both occur with probability 0.35. The chance of A or B occurring is
- A0.75
- B1.1
- C0.85
- D0.45
Section B: Structured questions[20 marks]
Answer all questions in the spaces provided. Show all your working.
- 11
A lucky dip contains 30 tickets, of which 12 are winning tickets.
- (a)
Find the probability of winning on a single dip.
[1] - (b)
A ticket is dipped, then replaced, and a second dip is made. Find P(two winning dips).
[2] - (c)
Find P(at least one of the two dips wins).
[2]
- (a)
- 12
A keyring holds three similar-looking keys, of which exactly one opens a door. The key is tried, and if it fails it is replaced and the try repeated.
- (a)
Write down the theoretical probability that one try opens the door.
[1] - (b)
In 120 tries the door opens 46 times. Calculate the relative frequency, giving your answer to 3 decimal places.
[2] - (c)
Comment on whether the experiment is consistent with the theoretical probability.
[2]
- (a)
- 13
A purse contains 4 gold and 6 silver coins. Two coins are taken out one after the other, and the first is not put back. (Extended)
- (a)
Find P(both coins are gold).
[2] - (b)
Find P(the two coins are the same colour).
[3]
- (a)
- 14
Of 50 athletes, 30 follow a new training plan and 20 do not. 24 of the trained athletes completed a marathon, along with 8 of the untrained athletes. (Extended)
- (a)
Complete the two-way table (trained / not trained against completed / did not complete).
[2] - (b)
One athlete is chosen at random. Find P(completed).
[1] - (c)
Given that an athlete completed the marathon, find the probability that they followed the training plan.
[2]
- (a)
— End of paper —