Question

A store is having a sale on walnuts and chocolate chips. For 12 pounds of walnuts and 2 pounds of chocolate chips, the total cost is $45. For 3 pounds of walnuts and 5 pounds of chocolate chips, the total cost is $18. Find the cost for each pound of walnuts and each pound of chocolate chips.

cost for each pound of walnuts:
cost for each pound of chocolate chips:

Answer 1

Each pound of walnuts cost $3.50 and each pound of chocolate chips cost $1.50

Explanation:

Let the cost of one pound of walnuts = $w

and the cost of one pound of chocolate chips = $c

Cost of 12 pounds of walnuts and 2 pounds of chocolate chips = $45

12w + 2c = 45 ------(1)

Cost of 3 pounds of walnuts and 5 pounds of chocolate chips = $18

3w + 5c = 18 --------(2)

Multiply equation (2) by 4 then subtract it from equation (1)

(12w + 2c) - (12w + 20c) = 45 - 72

-18c = -27

c =
`(27)/(18)`

c = $1.5

Substitute c = 1.5 in equation (1),

12w + 2(1.5) = 45

12w = 45 - 3

w =
`(42)/(12)`

w = $3.5

Therefore, each pound of walnuts cost $3.5 and each pound of chocolate chips cost $1.5