A swimming bath is 24 m long and 15 m broad. When a number of men drive into the bath. The height of water rises by 1cm. If the average volume of water displaced by each man be 0.1m3 how many mean are there in the both?

A. 9!/(2!)2 3!
B. 9!/(2!)3 3!
C. 9!/(2!)2 (3!)2
D. 5!/(2!)2 3!
Explanation:
n items of which p are alike of one kind, q alike of the other, r alike of another kind and the remaining are distinct can be arranged in a row in n!/p!q!r! ways.
The letter pattern ‘MESMERISE’ consists of 10 letters of which there are 2M’s, 3E’s, 2S’s and 1I and 1R.
Number of arrangements = 9!/(2!)2 3!

A. 4
B. 12
C. 18
D. None of these
Explanation:
Total number of ways = 2C1 . 5C2 = 2 x 5!/3!2! = 2 x 10 = 210