348
Q:

# Two cards are drawn at random from a pack of 52 cards.what is the probability that either both are black or both are queen?

 A) 52/221 B) 55/190 C) 55/221 D) 19/221

Explanation:

We have n(s) =$52C2$ 52 = 52*51/2*1= 1326.

Let A = event of getting both black cards

B = event of getting both queens

A∩B = event of getting queen of black cards

n(A) = $52*512*1$ = $26C2$ = 325, n(B)= $26*252*1$= 4*3/2*1= 6  and  n(A∩B) = $4C2$ = 1

P(A) = n(A)/n(S) = 325/1326;

P(B) = n(B)/n(S) = 6/1326 and

P(A∩B) = n(A∩B)/n(S) = 1/1326

P(A∪B) = P(A) + P(B) - P(A∩B) = (325+6-1) / 1326 = 330/1326 = 55/221

Q:

If the standard deviation of 0, 1, 2, 3 ......... 9 is K, then the standard deviation of 10, 11, 12, 13 ........... 19 will be:

 A) K+1 B) K C) K+4 D) K+8

Explanation:

1 682
Q:

The standard deviation of the set {10, 11, 12, 9, 8} is

 A) 1 B) √2 C) 2 D) 2√2

Explanation:

5 588
Q:

Find the range of the data 2, 1, 2, 3, 5, 4, 7, 3, 5, 2, 4.

 A) 5 B) 4 C) 3 D) 6

Explanation:

1 553
Q:

Find the median, mode and mean of 9, 5, 8, 9, 9, 7, 8, 9, 8.

 A) 9, 9, 9 B) 9, 8, 9 C) 8, 9, 8 D) 8, 9, 9

Explanation:

2 542
Q:

In the usual set notation,  =

 A) A∪B∪A∪C B) A∩B∪A∩C C) A∪B∩A∪C D) A∪B∩A∩C

Explanation:

0 2116
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:

1 719
Q:

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

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

Explanation:

2 747
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