Question

A grocer has two kinds of candies, one selling for 40 cents a pound and the other for $1.40 per pound. How many pounds of each kind must he use to make 100 pounds worth 85 cents a pound?

Answer 1

below

Explanation:

Candy x = 0.90 per pound

Candy y = 0.40 per pound

100 pounds * 0.85 per pound = 85

x + y = 100

0.90x + 0.40y = 85

x = 100 - y

0.90(100 - y) + 0.40y = 85

90 - 0.90y + 0.40y = 85

-0.50y = 85 - 90

y = -5 / -0.50

y = 10

x = 100 - y

x = 100 - 10

x = 90

0.90x + 0.40y = 85

0.90(90) + 0.40(10) = 85

81 + 4 = 85

85 = 85