34. Fill in the blank circle. 2 , 7 , 28 , 63 , 126 , ? , 344 , 511

Explanation

Here, `2 = 1^3+1`

`7 = 2^3-1`

`28 = 3^3+1`

`63 = 4^3-1`

`126 = 5^3+1`

Here, we are calculating the cube of the term and alternatively adding and subtracting `1` from it.

So, the sixth term will be, `6^3-1 = 215`