Odd Man Out and Series - General Aptitude

Q1:

7, 26, 63, 124, 215, 342, (....)

A 481

B 511

C 391

D 421

ANS:B - 511

Numbers are (23 - 1), (33 - 1), (43 - 1), (53 - 1), (63 - 1), (73 - 1) etc. So, the next number is (83 - 1) = (512 - 1) = 511.