Mean and standard deviation of $100$ observation were found to be $40$ and $10$ respectively . If at the times of calculation two observations were wrongly takes as $30$ and $70$ in place of $3$ and $27$ respectively. Find the correct standard deviation.

Question

$\begin{array}{1 1}(A)\; 39.30,10.24\\(B)\;1.6,1.4\\(C)\;16,10\\(D)\;6,45\end{array} $