Mathematics for IGCSE & O level - Probability (Section 3)
1
Two events are considered independent if:
პასუხი
(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?
პასუხი
(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?
პასუხი
(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?
პასუხი
(B)
3/50
5
If the probability of an event is 0.3, what is the probability of its complement (the event not happening)?
პასუხი
(C)
0.7
6
The sum of all outcomes from a tree diagram is always what?
პასუხი
(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?
პასუხი
(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?
პასუხი
(A)
1/13
9
A spinner has 4 equal sections: red, blue, green, and yellow. What is the probability the spinner lands on blue?
პასუხი
(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?
პასუხი
(B)
1/3
11
A fair coin is tossed twice. Which of the following is(are) correct?
პასუხი
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?
პასუხი
(C)
4/9
13
If the probability of winning a game is 0.6, then the probability of losing is:
პასუხი
(B)
0.4
14
What is the probability of drawing a king or a queen from a standard deck of 52 cards?
პასუხი
(C)
4/13
15
Which of the following is correct for the total probability for all the outcomes?
პასუხი
(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?
პასუხი
(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?
პასუხი
(B)
3/25
18
A survey of 50 people showed that 30 preferred vanilla ice cream. What is the relative frequency of preferring vanilla?
პასუხი
(B)
3/5
19
If the probability of an event happening is 0.2, what is the probability of the event *not* happening?
პასუხი
(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?
პასუხი
(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?
პასუხი
(A)
0.36
22
What is the probability of getting heads when you flip a fair coin?
პასუხი
(C)
1/2
23
If event A and event B are independent, which formula correctly calculates the probability of both events happening?
პასუხი
(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?
პასუხი
(A)
1/2
25
A die is rolled. What is the probability of getting a number less than 3?
პასუხი
(B)
1/3
26
Which of the following is a key point for the probability of an event?
პასუხი
(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?
პასუხი
(A)
3/8
28
What is the probability of getting tails when you flip a fair coin?
პასუხი
(C)
1/2
29
What is the probability of getting a 5 on a single roll of a standard six-sided die?
პასუხი
(C)
1/6
30
If two events cannot occur at the same time, they are considered:
პასუხი
(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?
პასუხი
(C)
1/10
32
The probability of a certain event occurring is 0.1. What is the probability of the event *not* occurring?
პასუხი
(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?
პასუხი
(B)
7/20
34
In the context of probability, the term 'trials' most closely represents:
პასუხი
(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?
პასუხი
(A)
1/36
36
What is the correct formula for P(A and B) if A and B are independent events?
პასუხი
(C)
P(A) * P(B)
37
Which statement is true about probability values?
პასუხი
(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?
პასუხი
(B)
1/2
39
A bag contains 7 white balls, 3 black balls. What's the probability of picking a black ball?
პასუხი
(A)
3/10
40
If the probability of event A is 0.6, what is the probability of the complement of A (not A)?
პასუხი
(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?
პასუხი
(B)
0.027
42
What is the probability of drawing a face card (Jack, Queen, or King) from a standard deck of 52 cards?
პასუხი
(C)
12/52
43
Consider a six-sided die. Which of the following events are possible when rolling the die?
პასუხი
A
B
D
44
The probability of an event is 0.7. What are the odds *against* that event happening?
პასუხი
(A)
3:7
45
A spinner has 3 equal sections: red, blue, and green. What is the probability of landing on blue?
პასუხი
(B)
1/3
46
What is the probability of getting a tail when you toss a fair coin?
პასუხი
(C)
1/2
47
If you flip a fair coin, what is the probability of getting heads?
პასუხი
(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?
პასუხი
(C)
1/2
49
What type of diagram is best used to find the probabilities when dealing with dependent events?
პასუხი
(C)
Tree Diagram
50
What are the odds against rolling a 6 on a standard six-sided die?
