Mathematics for IGCSE & O level - Probability (Section 2)
1
If two events, A and B, are independent, and the probability of A is 0.3 and the probability of B is 0.5, what is the probability of both A and B occurring?
Answer
(B)
0.15
2
If the probability that Rabia wins the 400-metre race is 0.3, what is the probability that she does NOT win?
Answer
(B)
0.7
3
If the probability that a student will pass an exam is 0.8, what is the probability that the student will fail?
Answer
(A)
0.2
4
If the first match is lost (probability 0.4), what is the probability they win one of the first two matches, given the following: The probability of winning the second match is 0.7 if the first match is won, otherwise it's 0.4?
Answer
(D)
0.28
5
What is the sample space for flipping a coin and rolling a six sided die?
Answer
A
B
6
Which events are independent?
Answer
A
C
7
A spinner is divided into 4 equal sections labeled 1, 2, 3, and 4. What is the probability of spinning a number greater than 2?
Answer
(B)
1/2
8
If the first match of the season is won by the team (probability 0.6), what is the probability they win at least one of the first two matches, given the following: The probability of winning the second match is 0.7 if the first match is won, otherwise it's 0.4?
Answer
(D)
0.66
9
A fair die is rolled twice. What is the probability of rolling a 3 on the first roll and an even number on the second roll?
Answer
(A)
1/12
10
If P(A) = 0.4 and P(B) = 0.2 and the events are independent, find P(A and B).
Answer
(C)
0.08
11
If the chance of rain tomorrow is 40%, what is the probability that it *will not* rain tomorrow?
Answer
(B)
0.6
12
A bag contains 4 red balls and 6 blue balls. If a ball is selected at random, what is the probability it is red?
Answer
(B)
2/5
13
What is the expected frequency of an event?
Answer
(B)
probability of an event occurring * total number of observations of an event
14
Two events are *mutually exclusive*. Event A has a probability of 0.4. Event B has a probability of 0.3. What is the probability of event A OR event B occurring?
Answer
(A)
0.7
15
If the probability of an event is 0.6, what are the odds against that event occurring?
Answer
(A)
2:3
16
What is the probability of not getting a head when tossing a fair coin?
Answer
(C)
1/2
17
When tossing a coin twice, what is the probability of getting a head followed by a tail? (Assume fair coin)
Answer
(A)
1/4
18
Two dice are rolled. What is the probability of rolling a sum of 2?
Answer
(A)
1/36
19
If you roll a six-sided die, what is the probability of *not* rolling a 1?
Answer
(C)
5/6
20
Which of the following are true about a probability distribution?
Answer
A
B
D
21
When the outcome of a second event depends on the outcome of the first event, the events are described as what?
Answer
(B)
Dependent
22
What is the probability of the first ball being green, and the second ball being blue, if there are 5 green balls, 3 red balls and 2 yellow balls and the ball is replaced?
Answer
(A)
3/25
23
What is the probability of drawing a club from a standard deck of 52 cards?
Answer
(C)
1/13
24
If the chance of snow tomorrow is 25%, what is the probability that it will not snow?
Answer
(C)
0.75
25
A survey of 100 people showed that 60 prefer coffee, 30 prefer tea, and 10 have no preference. What is the probability a person randomly selected from the survey prefers tea?
Answer
(A)
3/10
26
A bag contains 3 red, 5 blue, and 2 green marbles. What is the probability of selecting a green marble?
Answer
(B)
1/5
27
If the probability that it rains on Monday is 0.2 and the probability it rains on Tuesday is 0.3, what is the probability that it rains on both days, assuming the events are independent?
Answer
(C)
0.06
28
A spinner has 3 equal sections: labeled 1, 2, and 3. What is the probability of spinning a number greater than 1?
Answer
(B)
2/3
29
If a coin is tossed 100 times and lands on heads 60 times, what is the experimental probability of getting tails?
Answer
(A)
0.4
30
What are the possible outcomes when flipping a coin and rolling a six-sided die?
Answer
A
B
31
A dart is thrown at a circular target. The probability of hitting the bullseye is 0.05. What is the probability of *not* hitting the bullseye?
Answer
(B)
0.95
32
A spinner has four equal sections: red, blue, green, and yellow. What is the probability of the spinner landing on yellow?
Answer
(A)
1/4
33
If the events are independent, P(A) = 0.6 and P(B) = 0.4, what is P(A or B)?
Answer
(C)
0.76
34
What is the definition of 'expected frequency'?
Answer
(B)
probability of an event occurring multiplied by the number of trials
35
If two dice are rolled, what is the probability of getting a sum of 12?
Answer
(B)
1/36
36
If two events, A and B, are independent, and P(A) = 0.4 and P(B) = 0.5, what is the probability of both A and B occurring?
Answer
(B)
0.2
37
If the probability of a particular event happening is 0, then:
Answer
(B)
The event is impossible.
38
What is the probability of drawing a red card from a standard deck of 52 playing cards?
Answer
(B)
1/2
39
The probability that it will rain tomorrow is 0.3. What is the probability that it will *not* rain tomorrow?
Answer
(A)
0.7
40
A bag contains 6 red marbles and 4 blue marbles. If one marble is chosen at random, what is the probability that it is red?
Answer
(B)
3/5
41
If the probability of an event, A, is 0.4 and the probability of event B is 0.5, what is the probability that either A or B occurs if they are mutually exclusive?
Answer
(A)
0.9
42
In a standard deck of 52 cards, what is the probability of selecting a card that is a heart or a diamond?
Answer
(A)
1/2
43
Two events are considered mutually exclusive when:
Answer
(C)
They cannot both occur at the same time.
44
What is the relationship between relative frequency and probability?
Answer
(A)
Relative frequency is an estimate of probability.
45
Two events A and B are mutually exclusive and P(A) = 0.3, P(B) = 0.5. Find P(A or B).
Answer
(A)
0.8
46
If two events, A and B, are mutually exclusive, what is P(A and B)?
Answer
(B)
0
47
What are the odds in favor of drawing a heart from a standard deck of 52 playing cards?
Answer
(B)
1:3
48
If the chance of rain is 40%, what is the chance it will NOT rain?
Answer
(B)
60%
49
If the probability of an event occurring is 0.3, what is the probability of the event NOT occurring?
Answer
(B)
0.7
50
Which of the following describes the sample space of flipping a coin and then rolling a six-sided die?
