Question

In the given question, select the related number from the given alternatives.
$76$ $:$ $83$ $:$ $:$ $42$ $:$ $?$

• A. $34$
• B. $21$
• C. $12$
• D. $7$

Answer 1

The correct option is D $7$

$76\to 7\times \left(\frac{6}{2}\right)(\frac{6}{2}+1)-1$

i.e. $7\times 3\times 4-1=83$

$76:83$

Similarly,

$42\to 4\times \left(\frac{2}{2}\right)\times (\frac{2}{2}+1)-1$

i.e. $4\times 1\times 2-1=7$

Therefore $42:7$

Hence the answer is $7$.