217 x 217 + 183 x 183 = ?

Question: 217 x 217 + 183 x 183 = ?

[A].

79698

[B].

80578

[C].

80698

[D].

81268

Answer: Option B

Explanation:

(217)2 + (183)2	= (200 + 17)2 + (200 – 17)2
	= 2 x [(200)2 + (17)2]       [Ref: (a + b)2 + (a – b)2 = 2(a2 + b2)]
	= 2[40000 + 289]
	= 2 x 40289
	= 80578.