$${\left( {15} \right)^2} + {\left( {18} \right)^2} - 20 = \sqrt ? $$

A. 22

B. 23

C. 529

D. 279841

E. None of these

Answer: Option D

Solution(By Examveda Team)

$$\eqalign{ & {\text{Let, }} \cr & {\left( {15} \right)^2} + {\left( {18} \right)^2} - 20 = \sqrt x \cr & {\text{Then, }} \cr & \sqrt x = 225 + 324 - 20 \cr & \Leftrightarrow x = {\left( {529} \right)^2} \cr & \Leftrightarrow x = 279841 \cr} $$