3 Complete the series 7, 26, 63, 124, 215, 342, ?A 391B 511C 481D 421

The given series is: 7, 26, 63, 124, 215, 342, ?

This is a series of cubes plus one.

The pattern is as follows:

2^3 + 1 = 8 + 1 = 9 - 2 = 7 3^3 + 1 = 27 + 1 = 28 - 2 = 26 4^3 + 1 = 64 + 1 = 65 - 2 = 63 5^3 + 1 = 125 + 1 = 126 - 2 = 124 6^3 + 1 = 216 + 1 = 217 - 2 = 215 7^3 + 1 = 343 + 1 = 344 - 2 = 342

So, the next number in the series should be:

8^3 + 1 - 2 = 512 + 1 - 2 = 511

So, the answer is B 511.