Q.

The letters of the word COCHIN are permuted and all the permutations are arranged in an alphabetical order as in an English dictionary. The number of words that appear before the word COCHIN is                    [2007]

1 360  
2 192  
3 96  
4 48  

Ans.

(3)

The letters of the word COCHIN in alphabetical order are C,C,H,I,N,O.

Fixing first and second letters as C,C, the remaining 4 can be arranged in 4! ways.

Similarly, the words starting with each of CH,CI,CN are 4!

Then fixing first two letters as CO and next four places when filled in alphabetical order with remaining 4 letters give the word COCHIN.

 Number of words coming before COCHIN

       =4×4!=4×24=96