Question

Find out the wrong number in the series given below :
$7,28,63,124,215$

• A. $7$
• B. $124$
• C. $63$
• D. $28$

Answer 1

The correct option is D $28$

$1\text{st}$ term $=7=2^3-1$
$2\text{nd}$ term $=28\ne 3^3-1$
$3\text{rd}$ term $=63=4^3-1$
$4\text{th}$ term $=124=5^3-1$
$5\text{th}$ term $=215=6^3-1$
$\therefore 28$ is wrong.