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?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(D)
0.28
5
What is the sample space for flipping a coin and rolling a six sided die?
Απάντηση
A
B
6
Which events are independent?
Απάντηση
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?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(A)
1/12
10
If P(A) = 0.4 and P(B) = 0.2 and the events are independent, find P(A and B).
Απάντηση
(C)
0.08
11
If the chance of rain tomorrow is 40%, what is the probability that it *will not* rain tomorrow?
Απάντηση
(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?
Απάντηση
(B)
2/5
13
What is the expected frequency of an event?
Απάντηση
(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?
Απάντηση
(A)
0.7
15
If the probability of an event is 0.6, what are the odds against that event occurring?
Απάντηση
(A)
2:3
16
What is the probability of not getting a head when tossing a fair coin?
Απάντηση
(C)
1/2
17
When tossing a coin twice, what is the probability of getting a head followed by a tail? (Assume fair coin)
Απάντηση
(A)
1/4
18
Two dice are rolled. What is the probability of rolling a sum of 2?
Απάντηση
(A)
1/36
19
If you roll a six-sided die, what is the probability of *not* rolling a 1?
Απάντηση
(C)
5/6
20
Which of the following are true about a probability distribution?
Απάντηση
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?
Απάντηση
(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?
Απάντηση
(A)
3/25
23
What is the probability of drawing a club from a standard deck of 52 cards?
Απάντηση
(C)
1/13
24
If the chance of snow tomorrow is 25%, what is the probability that it will not snow?
Απάντηση
(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?
Απάντηση
(A)
3/10
26
A bag contains 3 red, 5 blue, and 2 green marbles. What is the probability of selecting a green marble?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(A)
0.4
30
What are the possible outcomes when flipping a coin and rolling a six-sided die?
Απάντηση
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?
Απάντηση
(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?
Απάντηση
(A)
1/4
33
If the events are independent, P(A) = 0.6 and P(B) = 0.4, what is P(A or B)?
Απάντηση
(C)
0.76
34
What is the definition of 'expected frequency'?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(B)
0.2
37
If the probability of a particular event happening is 0, then:
Απάντηση
(B)
The event is impossible.
38
What is the probability of drawing a red card from a standard deck of 52 playing cards?
Απάντηση
(B)
1/2
39
The probability that it will rain tomorrow is 0.3. What is the probability that it will *not* rain tomorrow?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(A)
1/2
43
Two events are considered mutually exclusive when:
Απάντηση
(C)
They cannot both occur at the same time.
44
What is the relationship between relative frequency and probability?
Απάντηση
(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).
Απάντηση
(A)
0.8
46
If two events, A and B, are mutually exclusive, what is P(A and B)?
Απάντηση
(B)
0
47
What are the odds in favor of drawing a heart from a standard deck of 52 playing cards?
Απάντηση
(B)
1:3
48
If the chance of rain is 40%, what is the chance it will NOT rain?
Απάντηση
(B)
60%
49
If the probability of an event occurring is 0.3, what is the probability of the event NOT occurring?
Απάντηση
(B)
0.7
50
Which of the following describes the sample space of flipping a coin and then rolling a six-sided die?
