Question

Find the square root of:

(7) 15625

Answer 1

Prime factorisation of 15625:

$\begin{array}{cc}5& 15625\\ 5& 3125\\ 5& 625\\ 5& 125\\ 5& 25\\ 5& 5\\ & 1\end{array}$

= 5 × 5 × 5 × 5 × 5 × 5
= (5 × 5 × 5)²

∴ Square root of 15625 = 5 × 5 × 5 = 125