30
Q:

# Two brother X and Y appeared for an exam. The probability of selection of X is 1/7 and that of B is 2/9. Find the probability that both of them are selected.

 A) 1/63 B) 1/14 C) 2/63 D) 1/9

Explanation:

Let A be the event that X is selected and B is the event that Y is selected.

P(A) = 1/7,  P(B) = 2/9.

Let C be the event that both are selected.

P(C) = P(A) × P(B) as A and B are independent events:

= (1/7) × (2/9)  = 2/63

Q:

Find the range and mode of the data 17, 18, 28, 19, 16, 18, 17, 29, 18

 A) 12 and 18 B) 13 and 18 C) 12 and 17 D) 11 and 17

Explanation:

5 304
Q:

Find the standard deviation of {11, 7, 10,13, 9}

 A) 1 B) 2 C) 4 D) 5

Explanation:

2 271
Q:

A table tennis player, lost 12 games out of 18 games played. Calculate the games won in terms of decimal.

 A) 0.667 B) 0.067 C) 0.50 D) 0.333

Explanation:

1 383
Q:

A sequence , has odd number of terms. Then the median is

 A) axn2+1 B) axn2-1 C) axn-1 D) axn2

Explanation:

3 2426
Q:

The mean of a distribution is 15 and the standard deviation is 5. What is the value of the coefficient variation?

 A) 16.66% B) 66.66% C) 33.33% D) 100%

Explanation:

5 618
Q:

If the standard deviation of a population is 3, what would be the population variance?

 A) 9 B) 6 C) 8 D) 15

Explanation:

3 3062
Q:

The variance of a set of data is 169. Then the standard deviation of the data is

 A) +-13 B) 13 C) 69 D) 84.5

Explanation:

3 2512
Q:

If the standard deviation of a population is 10, what would be the population variance?

 A) 100 B) 30 C) 5 D) 20