Given,

$\begin{array}{l}\sqrt{\text{624.9995}}{\text{ + (4.9989)}}^{\text{2}}\\ =?÷\frac{1}{\text{4.9900865}}\end{array}$

It can also be written as

 $$\begin{gathered} = \sqrt{625}+(5{)}^2?+\frac{1}{5} \\ =?\approx \frac{1}{5}(25+25) \\ = 0.2\times 50 \\ =10 \end{gathered}$$

Hence, Option Cis correct.