Question

Solve...(n -1)n(n+1)=990....What is the value of n

Answer 1

10 is the correct result.

(n+1)(n-1)n =990
(nsquare - 1)n=990
$(n {}^{3} - 1 )n = 990$





I used the hit and trial method by searching for the unit digit of n having the property that when ncube is subtracted by n it gives zero.