Pounds in nuts

Question

The manager of a speciality food store combined almonds that cost $6.50 per pound with walnuts that cost $5.50 per pound. How many pounds of each were used to make a 100 pound mixture that costs $5.87 per pound?

Answer 1

Bianca:

 

You can set up a system of linear equations to represent this.  There are two variables, the number of pounds of almonds purchased, and the number of pounds of walnuts purchased.  You can create an equation for the total amount of almonds purchased (total weight=100 pounds) and an equation for the average cost.

 

a = # of pounds of almonds purchased, and w = # of pounds of walnuts purchased

 

a + w = 100

 

(6.5a + 5.5w)/100 = 5.87

 

You can "clear the fraction" by multiplying by 100 to get the total cost of the 100 lbs of nuts.

6.5a + 5.5w = 587

 

You can solve the system using substitution or linear combination.

 

- Rob