if four times number of permutations of n things 3 together is equal tofive times number of permutation of n-1 things 3 together find n

Dear manisha

given   4* ⁿP₃   = 5* ^n-1P₃

           4*n!/(n-3)! = 5*(n-1)!/(n-4)!

           4n/(n-3) =5

            n=15

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