Q.

The letters of the word ‘MANKIND’ are written in all possible orders and arranged in serial order as in an English dictionary. Then the serial number of the word ‘MANKIND’ is

1 1492  
2 1493  
3 1490  
4 1491  

Ans.

(1)

MANKIND

(4×6!2!)+(5!×0)+(4!×32!)+(3!×2)+(2!×1)+(1!×1)+(0!×0)=1492

⇒1440+36+12+4=1492