Question

The number which exceeds its positive square root by 12 is.

• A. 9
• B. 16
• C. 25
• D. None of these

Answer 1

Answer: (B)

16

Answer 2

Let the required number is x

So, $a^{2} - c^{2} = - ab$

⇒ $a^{2} - c^{2} = ab$

⇒ $x,\mspace{6mu} y,\mspace{6mu} zu = x^{2} + 4y^{2} + 9z^{2} - 6yz - 3zx - 2xy$

Since $x$ does not hold the condition.

Trick : By inspection, since 16 exceeds its positive square root i.e.,4 by 12.