What is the least number to be added to 7700 to make it a perfect square ?

A. 77

B. 98

C. 131

D. 221

E. None of these

Answer: Option E

Solution(By Examveda Team)

$$\eqalign{ & \,\,\,\,\,8|\overline {77} \,\,\overline {00} \,\,(87 \cr & \,\,\,\,\,\,\,\,\,|\,\,64 \cr & \,\,\,\,\,\,\,\,\,| - - - - - - \cr & 167|\,\,\,13\,00 \cr & \,\,\,\,\,\,\,\,\,|\,\,\,11\,69 \cr & \,\,\,\,\,\,\,\,\,| - - - - - - \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,1\,31 \cr & \therefore {\text{Number to be added}} \cr & = {\left( {88} \right)^2} - 7700 \cr & = 7744 - 7700 \cr & = 44 \cr} $$