Question

Joyce wants to mix granola and raisins together to make a snack for her class. Granola costs $2 per pound and raisins cost $4.50 per pound. Joyce is willing to spend $37.50 and wants to make 15 pounds of trail mix. Which system of equations could Joyce use to figure out how many pounds of granola (g) and raisins (r) she should buy?

A) 35 pounds
B) 36 pounds
C) 54 pounds
D) 72 pounds 

(Please help me, I don't know how to do it)

Answer 1

g+r=15  and 2.00g+4.50r=37.50 are the two equations you need to use

Answer 2

Answer with explanation:

Let pounds of granola she buy be denoted by g and raisins be denoted by r.

Granola costs $2 per pound and raisins cost $4.50 per pound. Joyce is willing to spend $37.50 and wants to make 15 pounds of trail mix.

The system of equation is given as:

• 2g+4.50r=37.50-------(1)
• and g+r=15----------(2)

on solving the system of equation by method of elimination we get:

Multiply equation (2) by 2 we get:

2g+2r=30

Now, on subtracting equation (2) by equation (1) we get:

⇒ 2.50r=7.50

⇒ r=3

similarly we get g=12

Hence, we get the the amount of granola she should buy=12 pounds.

Amount of raisins she should buy=3 pounds.