Probability Aptitude Test Paper 3

11) A man tossed two dice. What is the probability that the total score is a prime number?

5/12
5/14
5/20
5/24

Answer: A

Explanation:

As per the question:
n (S) = 6*6 = 36
And, the event that the sum is a prime number:
E = {(1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4, 3),
(5, 2), (5, 6), (6, 1), (6, 5)}

So, n (E) = 15

Apti Probability

12) A card is drawn from a pack of 52 cards. What is the probability of getting a king of heart or a queen of club?

1/22
1/24
1/26
1/28

Answer: C

Explanation:

We have, n (S) = 52
The event of getting a king of heart or a queen of club = 2
So, n (E) = 2
Apti Probability

13) A box contains 4 white, 5 red, and 6 blue balls. If three balls are drawn at random from the box, what is the probability that all of them are blue?

4/91
4/81
4/71
4/61

Answer: A

Explanation:

As per the question, n(S) = number of ways of drawing 3 balls out of 15
Apti Probability

14) A man draws two cards at random from a pack of 52 cards. What is the probability that one is a spade and the other is a heart?

13/105
13/102
13/110
13/108

Answer: B

Explanation:

As per the question:
Apti Probability
Similarly, n (E) = number of ways of drawing 1 spade out of 13 and 1 heart out of 13.
= 13C1 * 13C1
= 13*13
= 169

15) Ram draws one card at random from a pack of 52 cards. What is the probability that the card drawn is a face card (jack, queen and king only)?

3/13
3/15
3/17
3/19

Answer: A

Explanation:

As per question: n(S) = 52 (as one card is drawn).
There are 12 face cards in a pack of 52 cards.
So, n (E) = 12
Now, the required probability, Apti Probability