Paper plates come in packages of 15 or 20. George bought 10 packages and had a total of 170 plates. How many of each package did he buy? (1 point)
3 packages of 15, 7 packages of 20
7 packages of 15, 3 packages of 20
4 packages of 15, 6 packages of 20
6 packages of 15, 4 packages of 20

Question

Paper plates come in packages of 15 or 20. George bought 10 packages and had a total of 170 plates. How many of each package did he buy?  (1 point)
3 packages of 15, 7 packages of 20
7 packages of 15, 3 packages of 20
4 packages of 15, 6 packages of 20
6 packages of 15, 4 packages of 20

anonymous · Answer

So combinations of 15 and 20 = 170 plates total. 
and the combination of plates = 10 packages. 

So set up two equations like this and solve for x and y using substitution.
15x +20 y = 170 
x + y = 10