Mathematics for IGCSE & O level - Probability (Section 1)
1
If two events are independent, how do you calculate the probability of both events occurring?
Answer
(C)
Multiply their individual probabilities
2
When is the sum of all the probabilities of the outcomes of an event equal to 1?
Answer
(A)
Always
3
What is the relative frequency of an event if it occurs 15 times in 75 trials?
Answer
(D)
15/75
4
If a fair die is rolled twice, what is the probability of rolling a 6 on both rolls?
Answer
(A)
1/36
5
Which of the following scenarios represents independent events?
Answer
B
C
D
6
In a class of 25 students, 10 students are wearing glasses. If a student is selected at random, what is the probability they are *not* wearing glasses?
Answer
(B)
3/5
7
A bag contains 8 green balls and 2 white balls. Two balls are selected without replacement. Which is/are the correct approach(es) to find the probability of selecting two balls of different colors?
Answer
A
B
C
8
When two events are mutually exclusive, what is the probability of both events occurring?
Answer
(A)
0
9
What is the probability of not rolling a 6 on a single roll of a standard six-sided die?
Answer
(C)
5/6
10
A jar contains 5 red, 7 green, and 3 blue marbles. What's the probability of choosing a red or green marble?
Answer
(D)
4/5
11
If there are 8 green balls and 2 white balls, two balls are selected without replacement. What is the probability of choosing two white balls?
Answer
(B)
1/45
12
What are the possible outcomes when tossing a coin?
Answer
A
B
13
In a bag with 6 red balls and 4 black balls. What is the probability of selecting 2 black balls, if the ball is not replaced?
Answer
(B)
2/15
14
What is the probability of rolling an odd number on a standard six-sided die?
Answer
(C)
1/2
15
A spinner is divided into 3 equal sections: red, green, and blue. What is the probability of the spinner landing on green?
Answer
(A)
1/3
16
A bag contains 4 red marbles and 6 blue marbles. If you pick one marble at random, what is the probability of picking a blue marble?
Answer
(B)
3/5
17
Which of the following pairs of events are mutually exclusive?
Answer
A
C
18
A fair six-sided die is rolled. What is the probability of rolling a 2?
Answer
(A)
1/6
19
Which events are independent?
Answer
A
D
20
If two events are mutually exclusive, which of the following statements is true?
Answer
(C)
The events cannot occur at the same time.
21
A spinner has 4 sections: Red, Green, Blue, and Yellow. Which of the following outcomes are possible if the spinner is spun once?
Answer
A
C
D
22
A die is rolled twice. What is the probability of getting a 6 on both rolls?
Answer
(C)
1/36
23
If the probability of an event is 1, then the event is:
Answer
(C)
Certain
24
What are the odds in favor of rolling a 4 on a standard six-sided die?
Answer
(A)
1:5
25
If you roll a six-sided die twice, what is the probability of rolling a 3 on the first roll and a 4 on the second roll?
Answer
(A)
1/36
26
A box contains 3 red, 5 green, and 2 yellow balls. What is the probability of picking a yellow ball?
Answer
(B)
1/5
27
Which of the following is a correct way to represent probability?
Answer
A
B
D
28
Which of the following are considered independent events?
Answer
A
B
D
29
If events A and B are mutually exclusive, and P(A) = 0.2 and P(B) = 0.3. What is the probability of either A or B?
Answer
(B)
0.5
30
What is the probability of *not* getting a tail when flipping a fair coin?
Answer
(B)
0.5
31
A spinner is divided into 8 equal sections, numbered 1 through 8. What is the probability of spinning a number greater than 5?
Answer
(B)
1/4
32
Which of the following scenarios represent mutually exclusive events?
Answer
A
B
D
33
Which events are mutually exclusive when drawing a single card from a standard deck of 52 cards?
Answer
B
C
34
In a class, 40% of the students are girls. If a student is selected randomly, what is the probability that the student is a boy?
Answer
(C)
0.6
35
What is the probability of flipping a coin and getting tails?
Answer
(C)
1/2
36
What is the probability of getting tails when flipping a fair coin?
Answer
(C)
1/2
37
A fair coin is flipped twice. What is the probability of getting two heads?
Answer
(B)
1/4
38
If two events, A and B, are independent, P(A) = 0.3 and P(B) = 0.6. What is the probability of A or B?
Answer
(D)
0.72
39
In a class, 10 students are wearing red shirts, 15 are wearing blue, and 5 are wearing green. What is the probability that a randomly selected student is wearing a blue shirt?
Answer
(B)
1/3
40
What is the probability of not getting a tail when you toss a fair coin once?
Answer
(C)
1/2
41
If the probability of a train arriving on time is 0.7, and the probability of the train being late is 0.3. What is the probability that the train is late on the first two days, but on time on the third day? (Independent events)
Answer
(B)
0.09
42
What is the probability of choosing a yellow ball on the second draw, given that the ball is not replaced?
Answer
(A)
Depends on the colour of the first ball chosen
43
What is the definition of relative frequency?
Answer
(C)
The ratio of the number of times an event occurs to the total number of trials.
44
What does the term "independent events" signify in probability?
Answer
(C)
Events where the occurrence of one does not influence the probability of the other.
45
What is the probability of getting heads when tossing a fair coin?
Answer
(C)
1/2
46
A die is rolled. What is the probability of rolling a number greater than 4?
Answer
(A)
1/6
47
A box contains 3 red balls, 4 green balls, and 5 blue balls. What is the probability of picking a green or red ball?
Answer
(B)
1/2
48
A standard deck of cards contains 52 cards. What is the probability of drawing a card that is a heart?
Answer
(C)
1/4
49
If the train is on time for two out of the three days, what is the probability? (Assume the probability of the train being on time is 0.7)
Answer
(B)
0.441
50
A card is drawn from a standard deck of 52 cards. What is the probability of drawing a spade?
