Question

In the given question, select the related number from the given alternatives.
$49$ $:$ $81$ $:$ $:$ $64$ $:$ $?$

• A. $36$
• B. $100$
• C. $121$
• D. $144$

Answer 1

Answer: (B)

$100$

The difference between the roots of second number and first number is 2, i.e. $\sqrt[2]{281}-\sqrt[2]{249}=2$.
Let the number we have to find be $x$.
Therefore $\sqrt[2]{2x}-\sqrt[2]{264}=2$
$\Rightarrow \sqrt[2]{2x}=10$
$\Rightarrow x=100$