Imagine a city grid that is like a rectangular coordinate system. You are currently at (0,0) and you want to get to corner (3,4). If a path consists of a series of eastward and northward moves, how many shortest paths are possible assuming that all streets and avenues are of the same length?

Help pls, I don't have any idea on how to solve this one. btw the answer is 35 paths.

-tnx