ABC26GN0180 · Number System

Subject: General Aptitude · Chapter: Number System · Exam: · Marks: · Difficulty:

$287 \times 287+269 \times 269-2 \times 287 \times 269=$ ?
(a)534
(b)446
(c)354
(d)324
(e)None of these
Answer
Answer (as printed): D
Explanation
$$\begin{aligned} (287 \times 287+269 \times 269- & 2 \times 287 \times 269) \\ & =(287)^{2}+(269)^{2}-(2 \times 287 \times 269) \\ & =(287-269)^{2}=(18)^{2}=324 . \\ & {\left[\because a^{2}+b^{2}-2 a b=(a-b)^{2}\right] } \end{aligned}$$

Explanation as extracted from the printed page; notation may be imperfect.

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