Question

1575 $\times$ is a perfect square.

• A. 7
• B. 5
• C. 4
• D. 6

Answer 1

The correct option is A 7

Prime factorisation of 1575:

$\begin{array}{cc}5& 1575\\ 5& 315\\ 3& 63\\ 3& 21\\ & 7\end{array}$

$1575=\underset{–}{5\times 5}\times \underset{–}{3\times 3}\times \underset{–}{7}InpairInpairNotinpair$

So, in order to achieve a perfect square, we need to multiply 1575 with 7.