For all $\displaystyle n\in{N}$ find a formula for $\displaystyle \sum{\sum{a_{ij}}}

$ (first sum between j=1 and n, second between i=1 and j) in each of the following cases:

i) $\displaystyle a_{ij}$ = 1

ii) $\displaystyle a_{ij}$ = ij

How would I go about this? Very confused.