Mathematics for IGCSE & O level - Probability (Section 3)
1
Two events are considered independent if:
Відповідь
(C)
The outcome of the second event is not affected by the outcome of the first.
2
If the probability of an event is 1, what does this indicate?
Відповідь
(C)
The event is certain.
3
In a survey of 200 people, 120 preferred coffee, 60 preferred tea, and 20 had no preference. What is the probability that a randomly selected person prefers coffee?
Відповідь
(B)
3/5
4
In a bag, there are 5 green balls, 3 red balls, and 2 yellow balls. If Jai chooses a ball at random, replaces it, and then chooses again, what is the probability that Jai's choices are red and yellow in any order?
Відповідь
(B)
3/50
5
If the probability of an event is 0.3, what is the probability of its complement (the event not happening)?
Відповідь
(C)
0.7
6
The sum of all outcomes from a tree diagram is always what?
Відповідь
(B)
1
7
A jar has 5 blue marbles and 5 red marbles. What is the probability of drawing a blue marble OR a red marble?
Відповідь
(C)
1
8
A card is drawn at random from a standard deck of 52 playing cards. What is the probability of drawing a King?
Відповідь
(A)
1/13
9
A spinner has 4 equal sections: red, blue, green, and yellow. What is the probability the spinner lands on blue?
Відповідь
(A)
1/4
10
What is the probability of rolling a multiple of 3 when you spin a fair spinner numbered from 1 to 6?
Відповідь
(B)
1/3
11
A fair coin is tossed twice. Which of the following is(are) correct?
Відповідь
A
B
D
12
If the probability of an event is 1/3, and it is repeated twice, what is the probability that the event happens exactly once?
Відповідь
(C)
4/9
13
If the probability of winning a game is 0.6, then the probability of losing is:
Відповідь
(B)
0.4
14
What is the probability of drawing a king or a queen from a standard deck of 52 cards?
Відповідь
(C)
4/13
15
Which of the following is correct for the total probability for all the outcomes?
Відповідь
(C)
1
16
A box contains 5 red, 3 blue, and 2 green marbles. If you pick one marble, replace it, and then pick another, what is the probability of picking a red marble and then a blue marble?
Відповідь
(A)
3/20
17
In a bag, there are 5 green balls, 3 red balls, and 2 yellow balls. If Jai chooses a ball at random, replaces it, and then chooses again, what is the probability that both of Jai's choices are red?
Відповідь
(B)
3/25
18
A survey of 50 people showed that 30 preferred vanilla ice cream. What is the relative frequency of preferring vanilla?
Відповідь
(B)
3/5
19
If the probability of an event happening is 0.2, what is the probability of the event *not* happening?
Відповідь
(C)
0.8
20
What is the probability of drawing a red ball, not replacing it, and then drawing a red ball again, if there are 7 red balls and 3 yellow balls to begin with?
Відповідь
(C)
7/30
21
A bag contains 6 red balls and 4 black balls. Gita selects a ball, notes its color and replaces it. What is the probability Gita selects two red balls?
Відповідь
(A)
0.36
22
What is the probability of getting heads when you flip a fair coin?
Відповідь
(C)
1/2
23
If event A and event B are independent, which formula correctly calculates the probability of both events happening?
Відповідь
(C)
P(A and B) = P(A) * P(B)
24
A bag contains 10 balls numbered 1 to 10. What is the probability of drawing an even-numbered ball?
Відповідь
(A)
1/2
25
A die is rolled. What is the probability of getting a number less than 3?
Відповідь
(B)
1/3
26
Which of the following is a key point for the probability of an event?
Відповідь
(B)
number of outcomes that give the event/total number of outcomes
27
A bag contains 3 red marbles and 5 blue marbles. What is the probability of choosing a red marble?
Відповідь
(A)
3/8
28
What is the probability of getting tails when you flip a fair coin?
Відповідь
(C)
1/2
29
What is the probability of getting a 5 on a single roll of a standard six-sided die?
Відповідь
(C)
1/6
30
If two events cannot occur at the same time, they are considered:
Відповідь
(C)
Mutually exclusive
31
A bag contains 4 blue and 6 green marbles. If a marble is selected at random, what is the probability it is *not* blue?
Відповідь
(C)
1/10
32
The probability of a certain event occurring is 0.1. What is the probability of the event *not* occurring?
Відповідь
(B)
0.9
33
A box contains 20 marbles: 8 are red, 7 are blue, and 5 are green. What is the probability of selecting a red marble?
Відповідь
(B)
7/20
34
In the context of probability, the term 'trials' most closely represents:
Відповідь
(B)
The total number of times an experiment is performed.
35
A die is rolled twice. What is the probability of rolling a 1 on the first roll and a 6 on the second roll?
Відповідь
(A)
1/36
36
What is the correct formula for P(A and B) if A and B are independent events?
Відповідь
(C)
P(A) * P(B)
37
Which statement is true about probability values?
Відповідь
(B)
Probability values always range from 0 to 1, inclusive.
38
A jar contains 2 red marbles, 3 blue marbles, and 5 green marbles. If you pick one marble, what is the probability it is green?
Відповідь
(B)
1/2
39
A bag contains 7 white balls, 3 black balls. What's the probability of picking a black ball?
Відповідь
(A)
3/10
40
If the probability of event A is 0.6, what is the probability of the complement of A (not A)?
Відповідь
(B)
0.4
41
If the probability of a train arriving on time is 0.7, what is the probability that the train is late on three consecutive days, assuming the events are independent?
Відповідь
(B)
0.027
42
What is the probability of drawing a face card (Jack, Queen, or King) from a standard deck of 52 cards?
Відповідь
(C)
12/52
43
Consider a six-sided die. Which of the following events are possible when rolling the die?
Відповідь
A
B
D
44
The probability of an event is 0.7. What are the odds *against* that event happening?
Відповідь
(A)
3:7
45
A spinner has 3 equal sections: red, blue, and green. What is the probability of landing on blue?
Відповідь
(B)
1/3
46
What is the probability of getting a tail when you toss a fair coin?
Відповідь
(C)
1/2
47
If you flip a fair coin, what is the probability of getting heads?
Відповідь
(C)
1/2
48
If the probability of rolling a prime number on a six-sided die is 1/2, what is the probability of *not* rolling a prime number?
Відповідь
(C)
1/2
49
What type of diagram is best used to find the probabilities when dealing with dependent events?
Відповідь
(C)
Tree Diagram
50
What are the odds against rolling a 6 on a standard six-sided die?
