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

Answer: Option E

$$\begin{array}{rl}& 8|\overline{77}\overline{00}(87\\ & |64\\ & |------\\ & 167|1300\\ & |1169\\ & |------\\ & 131\\ & \therefore \text{Number to be added}\\ & ={\left(88\right)}^2-7700\\ & =7744-7700\\ & =44\end{array}$$