Question

$\text{Identify the square of}39\text{from the}$
$\text{following.}$

• A. $78$
• B. $1521$
• C. $351$
• D. $1531$

Answer 1

The correct option is B

$1521$

$\text{The number 39 ends with 9.}\text{And}{9}^2=81\text{which ends with 1.}\text{Hence,}{39}^2\text{should have 1 in the units}\text{place.}$

$\text{We can observe from options that}\text{only 1521 satisfies this.}\text{Hence 1521 is the square of 39.}$