Find the odd one out in the given series:
10, 30, 68, 130, 220, 350
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 220
The terms grow faster and faster, which points to cubes. Each term is \(n^3+n\) for \(n=2,3,4,\ldots\):
\(2^3+2=10\)
\(3^3+3=30\)
\(4^3+4=68\)
\(5^3+5=130\)
\(6^3+6=222\), but the series has 220
\(7^3+7=350\)
220 does not follow the rule, so 220 is the odd one out.