Probability question from Kaplan Cat test

This topic has expert replies
Source: — Problem Solving |

Senior | Next Rank: 100 Posts
Posts: 59
Joined: Fri Feb 29, 2008 9:00 am
Thanked: 4 times

by agoyal2 » Sun Nov 30, 2008 1:28 am
Total number of ways of arranging 8 letters = 8!

Since A is repeated twice and B is repeated thrice, their order does not matter, hence divide 8! by 2! (ways of arranging two A's) and 3! (Ways of arranging B's).

Now, D must be right of C. Out of all the combinations, half of them will have D in the right of C and half in the left.

So, final answer = (8!)/(2!*3!*2)

Hope this helps