ABC26GN0186 · Number System

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

$(80)^{2}-(65)^{2}+81=$ ?
(a)306
(b)2094
(c)2175
(d)2256
(e)None of these
Answer
Answer (as printed): D
Explanation
$$\begin{aligned} & (80)^{2}-(65)^{2}+81=(80+65)(80-65)+81=(145 \times 15) \\ & +81=(2175+81)=2256 . \end{aligned}$$

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

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