Julius has three times as many stamps in his collection as his friends Liam andMario combined. Liam has 10 stamps in his collection. Julius has 87 stamps in his collection. How many stamps does Mario have in his collection?
We know Julius has 87 stamps. Liam has 10. Then let the number of stamps Mario have be x. We know Julius has three times as many stamps as Liam+Mario so we form an equation.
Therefore Mario has 19 stamps.