You can get cheap prizes for $0.35 each, or nicer prizes for $1.20 each.

You have been given the assignment to buy 150 prizes for a school carnival. You can get cheap prizes for $0.35 each, or nicer prizes for $1.20 each. If you only have $100 to spend, what is the maximum number of nicer prizes you can afford (and still get the 150 prizes you need)?