I have a list of dollar values listed in column A. I have assign a category
in column B to each of them. I want to add them by category.

So for an example:

A1 = 10.00 B1= Rent
A2 = 25.00 B2= Gas
A3 = 5.00 B3 = Rent
A4 = 100.00 B4= Gas

Now I want to say - Add Rent and give me the total in C12.
Add Gas and give me the total in C13.

Please help

Thanks