a) If you are required to walk from intersection A
to intersection B along a route that is confined
to the square grid of four avenues and three
streets shown in the map above, how many
routes from A to B can you take that have the
minimum possible length ?

What if 4 avenues and 4 streets.

What if 5 avenues and 3 streets

What if 4 avenues and 5 streets?

Just want to know method to calculate???