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)
$$\eqalign{ & \,\,\,\,\,8|\overline {77} \,\,\overline {00} \,\,(87 \cr & \,\,\,\,\,\,\,\,\,|\,\,64 \cr & \,\,\,\,\,\,\,\,\,| - - - - - - \cr & 167|\,\,\,13\,00 \cr & \,\,\,\,\,\,\,\,\,|\,\,\,11\,69 \cr & \,\,\,\,\,\,\,\,\,| - - - - - - \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,1\,31 \cr & \therefore {\text{Number to be added}} \cr & = {\left( {88} \right)^2} - 7700 \cr & = 7744 - 7700 \cr & = 44 \cr} $$This Question Belongs to Arithmetic Ability >> Square Root And Cube Root
Actually the third option which suggests
221 is the right option because when we add 7700 + 221 the resulting value is 89*89 = 7921 so correct option is d as well