Question

In the given question, select the related number from the given alternatives.
$10$ $:$ $99$ $:$ $:$ $9$ $:$ $?$

• A. $49$
• B. $80$
• C. $69$
• D. $79$

Answer 1

Answer: (B)

$80$

$99={10}^2-1=100-1$

Similarly,

$80=9^2-1=81-1$

Hence, B is the correct option.