Question

Nathan's boy scout troop is making M&M and peanut trail mix for a future hike. The M&M's cost $3 per pound and the peanuts cost $2 per pound. The boy scouts spend $74 to make 30 pounds of trail mix. How many pounds of M&M's did they buy?

Answer 1

x - pounds of the M&M`s;
y - pounds of the peanuts
x + y = 30
3 x + 2 y = 74
----------------------
y = 30 - x
3 x + 2 ( 30 - x ) = 74
3 x + 60 - 2 x = 74
x = 74 - 60
x = 14
Answer:
They bought 14 pounds of M&M`s.