# Probability Aptitude Test Paper 2

6) What is the probability of getting a sum 5 from two throws of a dice?

1. 1/9
2. 1/8
3. 1/7
4. 1/6

Explanation:

In two throws a dice, n (S) = 6 * 6 = 36
Let E is the event of getting a sum of five.
E = (1, 4), (4, 1), (2, 3), (3, 2)
So, n (E) = 4
So, P (E) = = 4/36 or 1/9

7) A man throws two dice simultaneously on the floor. What is the probability of getting two numbers whose product is even? Explanation:

In a simultaneous throw of the two dice, the sample space, S = 6 * 6 = 36
So, n (S) = 36

The event "E" = {(1, 2), (1, 4), (1, 6), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6), (3, 2), (3, 4),
(3, 6), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6), (5, 2), (5, 4), (5, 6), (6, 1),
(6, 2), (6, 3), (6, 4), (6, 5), (6, 6)}
So, n (E) = 27

Apply formula: 8) In a group of students, there are 15 boys and 10 girls. If three students are selected at random, what is the probability that 1 girl and 2 boys are selected?

1. 21/46
2. 21/36
3. 21/26
4. 21/56

Explanation:

Let sample space = S.
n (S) = number of ways to select 3 students ( 1 girl and 2 boys) out of 25 students
= 25C3 = 2300
n (E) = 10C1 * 15C2
=10 * = 1050

Apply formula: 9) In a lottery, there are 5 prizes and 35 blanks. If a lottery is drawn at random what will be the probability of getting a prize?

1. 1/5
2. 1/6
3. 1/7
4. 1/8

Explanation:

n (S)= 5 + 35
= 40
n (E)= 5
So, the probability of getting a prize, P (E) = 10) A man draws two cards together from a pack of 52 cards. What is the probability of both the cards being kings?

1. 1/111
2. 1/121
3. 1/221
4. 1/321

Explanation:

Let S be the sample space. E is the event of getting 2 kings out of 4.  Probability Aptitude Test Paper 1
Probability Aptitude Test Paper 3   