Arithmetic Ability
Permutations and Combinations

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Q.

If the letters of the word SACHIN are arranged in all possible ways and these words are written out as in dictionary, then the word ‘SACHIN’ appears at serial number :

View Answer

Correct choice: A

Explanation:

If the word started with the letter A then the remaining 5 positions can be filled in 5! Ways. If it started with c then the remaining 5 positions can be filled in 5! Ways.Similarly if it started with H,I,N the remaining 5 positions can be filled in 5! Ways. If it started with S then the remaining position can be filled with A,C,H,I,N in alphabetical order as on dictionary. The required word SACHIN can be obtained after the 5X5!=600 Ways i.e. SACHIN is the 601th letter.
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