57
Q:

# A word consists of 9 letters; 5 consonants and 4 vowels.Three letters are choosen at random. What is the probability that more than one vowel will be selected ?

 A) 13/42 B) 17/42 C) 5/42 D) 3/14

Explanation:

3 letters can be choosen out of 9 letters in $9C3$ ways.

More than one vowels ( 2 vowels + 1 consonant  or  3 vowels ) can be choosen in $(4C2*5C1)+4C3$ ways

Hence,required probability = $4C2*5C1+4C39C3$ = 17/42

Q:

X attempts 100 questions and gets 340 marks. If for every correct answer is 4 marks and wrong answer is negative one mark, then the number of questions wrongly answered by Mr. X is:

 A) 14 B) 15 C) 12 D) 13

Explanation:

7 756
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:

2 1275
Q:

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

 A) 1 B) √2 C) 2 D) 2√2

Explanation:

8 959
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 1204
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:

4 968
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:

1 3401
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 1174
Q:

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

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