InterviewSolution
Saved Bookmarks
| 1. |
Find n"if" P (n,4)=12.P(n,2) |
|
Answer» SOLUTION :`""^nP_4=12xx""^nP_2` ` or,(N!)/((n-4)!)=12xx(n!)/((n-2)!)` `or, (n-2)! =12(n-4)!` `or,(n-2)(n-3)(n-4)! =12(n-4)!` `or,(n-2)(n-3)=12` `or,n^2-5n-6=60` `(n-6)(n+1)=0` `or, n=6-1` HENCE `n=6` as n is a natural NUMBER. |
|