This word problem set involves solving systems of equations equations working with two different totals, typically a total price and total quantity. These are similar to the coin problems. There are 10 problems of increasing difficulty with full written out solution keys. Substitution is demonstrated in the answer keys to solve these problems. One method for use could be to demonstrate 5 problems in class and have the students solve the remaining 5 for homework. In a 45 minute block, I typically introduce the "coin" problem set and this problem set on the same day. If your students are just beginning to solve word problems, I have a free graphic organizer that might help.