Mean values for TWO variables

I've been out of college for several years now and although I did well in math, I cannot remember how to approach this problem. Could you help?

Here's what I have, a data set with a good sample size, N=2234. Each entry has **quantities q(A), q(B), Total weight of A + B combined.** I'm trying to find the average weight of A and the average weight of B.

If that's confusing, let me try this another way:

44 of object A, 39 of object B, total weight 6781 pounds

61 of object A, 42 of object B, total weight 9102 pounds

I have the quantities of A and B, and the total weight, but I'm interested in the average values of A and B over the course of 2234 observations.