How would i solve for n

Question

nP5 = 14(nP4)

Answer 1

nP5 = n!/(n-5)!

your equation:
n!/(n-5)! = 14n!/(n-4)!
n!/(n-5)! = 14n!/(n-4)(n-5)!
1 = 14/(n-4)
n-4 = 14
n = 18

check:
my calculator says P(18,5) = 1028160
and P(18,4) = 73440
and 14(73440) = 1028160