Ok, here is a problem that I have been stuck on for a while and can't make any sense of on how to even start the formula. Can someone please help me with how to get a formula from here and what I need to do? Also is there any suggestions for sites that can help me learn how to get the formulas from word problems that someone can recommend? Here is the problem:

Supplies recently sold a wirebound graph paper notebook for $2.50 and a college ruled notebook made of recycled paper for $2.30. At the start of a recent sping semester, a combination of 50 of these notebooks was sold for a total of $118.60. How many of each type were sold.

I hope someone can help me soon. thanks mica.