Mystery Candy Bags

We are learning about systems of equations in my small HS math class.  Tomorrow, we will do mystery candy bags.  I have done this before and used a scale and had one equation be their weights, but the scale was so sensitive that the answers were always off.  So, I simplified it up and removed the scale/weights.  I used Rolos, Kisses, and Peanut Butter cups.  Each bag has at least one of each. 

Last year I gave the kids the bag to solve but they squeezed it and tried to "feel" the answer.  This year, they will see the bag - but no touching until they have done the math and have their guess.  They will get an index card with some information on it:

There are 3 unknowns, so they will have to come up with three equations.  I have a small class, so I only need 4 bags of mystery candy.  You could do this without doing the bags of candy but it makes it more mysterious and the kids are motivated to solve it.  I typed up all of the information for all the bags so when they are done, they can try to solve the other bags as well.  Mystery Candy Worksheet