IIT JEE , AIEEE Forum - Mathematics , Algebra

sidrocks

the letters of the world 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.........

dr.dane

titun

The following arrangements will appear before COCHIN

CC - - - -
CH - - - -
CI - - - -
CN - - - -

In each case, the last four letters can be filled up in 4 ! ways ( as the last 4 letters in each of the case are distinct )

So, there are 4 ! x 4 words i.e 24 x 4 or 96 words before COCHIN.

Now, with CO as the two starting letters COCHIN is the first word as CHIN are already arranged alphabetically according to the dictionary.

So, in total 96 words will appear in dictionary before COCHIN

Ans : 96 words will appear in dictionary before COCHIN

Cheers !!!

sidrocks

Dr.dane you must give full solution & for your knowledge ur ans.is wrong.in fact titun's ans. is correct

shub

c is the first alphabet out of d letters in cochin.
let cc be d first 2 letters....no. of such words= 4P4=24
similarly there can be 24 letters by keeping ch,ci and cn constant....
cochin will be d first word when co is kept constant.
therefore total possible ways= 4*24=96

hope u understood

aravindh_ramaswamy

Hi!

96 is the ans.

It came in IIT-JEE this year ,right?

Oldisgold

Agree with Titun. rgds.

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