Simplification question for IBPS, SBI, RBI, clerk, PO, UPSC, State-PSC, Railways, SSC

[Q] (723+1992)2−(723−1992)2723×1992          = ?
(a) 1
(b) 2
(c) 3
(d) 4

Solution

Answer    (d)
Explanation
===(723+1992)2−(723−1992)2723×1992(a+b)2−(a−b)2ab(where a = 723 and b = 1992)a2+2ab+b2−(a2−2ab+b2)ab4ab4=4