In how many ways can 10 examination papers be arranged so that the best and the worst papers never come together? Pick one
A) 8*9! B) 8*8! C) 7*9! D) 9*8! E) None
Solution: No. of ways in which 10 paper can arranged is 10! Ways.   When the best and the worst papers come together, regarding the two as one paper, we have only 9 papers.   These 9 papers can be arranged in 9! Ways.   And two papers can be arranged themselves in 2! Ways.   No. of arrangement when best and worst paper do not come together,   = 10!- 9!.2! = 9!(10-2) = 8.9!.   8*9!nswer 8*9!
<result>A</result>
In how many ways can 10 examination papers be arranged so that the best and the worst papers never come together?