Question: If (n + 2)! = 60 [(n − 1)!], find n.
Solution:
(n + 2)! = 60 [(n − 1)!]
$\Rightarrow(n+2) \times(n+1) \times(n) \times(n-1) !=60[(n-1) !]$
$\Rightarrow(n+2) \times(n+1) \times(n)=60$
$\Rightarrow(n+2) \times(n+1) \times(n)=5 \times 4 \times 3$
∴ n = 3
