how many pounds of pecans must be mixed with three pound of walnuts?

Question

A candy store sells walnuts for $6 per pound, and pecans for $2 per pound. If the store wants to create a bag of mixed nuts that sells for $4 per pound, how many pounds of pecans must be mixed with three pound of walnuts?

Answer 1

Well, I ask you this:

How much does one half pound of each nut sell for?