Question

The least number which is a perfect square and has $540$ as a factor is:

• A. $8,100$
• B. $6,400$
• C. $4,900$
• D. $3,600$

Answer 1

The correct option is A $8,100$

$540=2^2\times 3^2\times 3\times 5$

$3$ and $5$ are odd one out so to make it perfect square we need to multiply $540$ by $3$ and $5$ to couple them.

$\therefore$ number is $2^2\times 3^2\times 3^2\times 5^2=8100$