Mathematics for IGCSE & O level - Probability (Section 1)
1
If two events are independent, how do you calculate the probability of both events occurring?
Απάντηση
(C)
Multiply their individual probabilities
2
When is the sum of all the probabilities of the outcomes of an event equal to 1?
Απάντηση
(A)
Always
3
What is the relative frequency of an event if it occurs 15 times in 75 trials?
Απάντηση
(D)
15/75
4
If a fair die is rolled twice, what is the probability of rolling a 6 on both rolls?
Απάντηση
(A)
1/36
5
Which of the following scenarios represents independent events?
Απάντηση
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?
Απάντηση
(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?
Απάντηση
A
B
C
8
When two events are mutually exclusive, what is the probability of both events occurring?
Απάντηση
(A)
0
9
What is the probability of not rolling a 6 on a single roll of a standard six-sided die?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(B)
1/45
12
What are the possible outcomes when tossing a coin?
Απάντηση
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?
Απάντηση
(B)
2/15
14
What is the probability of rolling an odd number on a standard six-sided die?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(B)
3/5
17
Which of the following pairs of events are mutually exclusive?
Απάντηση
A
C
18
A fair six-sided die is rolled. What is the probability of rolling a 2?
Απάντηση
(A)
1/6
19
Which events are independent?
Απάντηση
A
D
20
If two events are mutually exclusive, which of the following statements is true?
Απάντηση
(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?
Απάντηση
A
C
D
22
A die is rolled twice. What is the probability of getting a 6 on both rolls?
Απάντηση
(C)
1/36
23
If the probability of an event is 1, then the event is:
Απάντηση
(C)
Certain
24
What are the odds in favor of rolling a 4 on a standard six-sided die?
Απάντηση
(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?
Απάντηση
(A)
1/36
26
A box contains 3 red, 5 green, and 2 yellow balls. What is the probability of picking a yellow ball?
Απάντηση
(B)
1/5
27
Which of the following is a correct way to represent probability?
Απάντηση
A
B
D
28
Which of the following are considered independent events?
Απάντηση
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?
Απάντηση
(B)
0.5
30
What is the probability of *not* getting a tail when flipping a fair coin?
Απάντηση
(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?
Απάντηση
(B)
1/4
32
Which of the following scenarios represent mutually exclusive events?
Απάντηση
A
B
D
33
Which events are mutually exclusive when drawing a single card from a standard deck of 52 cards?
Απάντηση
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?
Απάντηση
(C)
0.6
35
What is the probability of flipping a coin and getting tails?
Απάντηση
(C)
1/2
36
What is the probability of getting tails when flipping a fair coin?
Απάντηση
(C)
1/2
37
A fair coin is flipped twice. What is the probability of getting two heads?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(B)
1/3
40
What is the probability of not getting a tail when you toss a fair coin once?
Απάντηση
(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)
Απάντηση
(B)
0.09
42
What is the probability of choosing a yellow ball on the second draw, given that the ball is not replaced?
Απάντηση
(A)
Depends on the colour of the first ball chosen
43
What is the definition of relative frequency?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(C)
1/2
46
A die is rolled. What is the probability of rolling a number greater than 4?
Απάντηση
(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?
Απάντηση
(B)
1/2
48
A standard deck of cards contains 52 cards. What is the probability of drawing a card that is a heart?
Απάντηση
(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)
Απάντηση
(B)
0.441
50
A card is drawn from a standard deck of 52 cards. What is the probability of drawing a spade?
