Question

In the given question, select the related number from the given alternatives.
$4$ $:$ $12$ $:$ $:$ $5$ $:$ $?$

• A. $25$
• B. $20$
• C. $22$
• D. $30$

Answer 1

Answer: (B)

$20$

The relation between the numbers is $n_1:n_2$ where, $n_1=n_1\times (n_1-1)$ .
Thus,
$4\times (4-1)$$\Rightarrow 4\times 3=12$
and
$5\times (5-1)$$\Rightarrow 5\times 4=20$