Hey all, I need some guidance on a problem I've been working on involving a grid formula. Please see the problem below:

(i) Consider anxngrid of uniform size. Guess a formula for the number of different squares (of varying size) and prove it.

Attachment 22869

Above is an illustration for a 2 x 2 grid.

(ii) What is your answer when we consider the same problem for amxngrid?

Not sure where to start off with this one....all help is appreciated!