Question

Which number should be multiplied to 1575 to make it a square number?

• A. 4
• B. 5
• C. 6
• D. 7

Answer 1

The correct option is D

7

Prime factorization 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 to make it a perfect square, we need to multiply 1575 with 7.