What is the sum of cubes in a series up to 'n' terms?

[draotic]

Homework Statement

find the sum of the series to 'n' terms
(1^3 / 1 ) + (1^3 + 2^3 / 1+2 ) + (1^3 + 2^3 + 3^3 / 1+2+3 ) +...

Homework Equations

sigma n^2 = n(n+1)(2n+1) / 6
sigma n = n(n+1) / 2

The Attempt at a Solution

numerator = 1^3 + 2^3 + ... n^3
denominator = 1+2+3+...n
...
my answer comes out to be n(n+1) / 2 , but i think that's wrong...
please lead me

 

[amal]

That is the last term you are calculating. And anyway, the question says Sum of cubes (not squares) in numerator. If you evaluate first few terms, you get 1+3+6+10+15+...
I think you can work this out.