Question

In each of the following question, select the related number from the given alternatives.
$48$ $:$ $122$ $:$ $:$ $168$ $:$ $?$

• A. $292$
• B. $290$
• C. $225$
• D. $215$

Answer 1

Answer: (B)

$290$

The pairs are made around an integer $x$ such that:
$x^2-1:(x+4{)}^2+1$
For $48$, take $x=7$
$7^2-1:(7+4{)}^2+1\Rightarrow (49-1):(121+1)\Rightarrow 48:122$
Now, $168=169-1={13}^2-1$
So, $x=13$ gives
${13}^2-1:(13+4{)}^2+1\Rightarrow (169-1):(289+1)\Rightarrow 168:290$

Hence, the missing number is $290$.