Question

In the given question, select the related number from the given alternatives.
$123$ $:$ $36$ $:$ $:$ $221$ $:$ $?$

• A. $52$
• B. $69$
• C. $72$
• D. $25$

Answer 1

Answer: (D)

$25$

Given that,

$123:36::221:?$

The first set, $123:36$ is related as, $123$ has sum of its digits $=1+2+3=6$

and $6^2=36$

Similarly, sum of digits of $221=2+2+1=5$ and $5^2=25$

$\Rightarrow 123:36::221:25$