Name: Travis
Who is asking: Student
Level: Middle

Question:
An art teacher buys exactly 100 items at this sale, and the total cost before tax is $100. She buys at least one of each item. How many of each item does she buy?

Markers $0.50
Sketch Pads $3.00
Paint Sets $10.00

Let M stand for Markers, S for Sketch pads & P for Paint Sets. You have M, S, P > 0;

Subtract the first equation from twice the second equation; you should be able to deduce the value of P knowing that it is an integer from the set {1, 2, ... , 9} and the fact that if something divides one side of an equation it divides the other. This makes it not too hard to then find M & S.