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Question
If (n+2)! = 60[(n–1)!], find n
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Solution
Given that (n + 2)! = 60(n – 1)!
(n + 2) (n + 1) n (n – 1)! = 60(n – 1)!
Cancelling (n – 1)! we get,
(n + 2)(n + 1)n = 60
(n + 2)(n + 1)n = 5 × 4 × 3
Both sides we consecutive product of integers
∴ n = 3
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