Question

A store owner has some coffee worth $1.80 per kg and some worth $2.80 per kg. He wants to make 60 kg of a mixture that will be worth $2.20 per kg. How many kgs of each type of coffee should he use?​

Answer 1

36 kg of the first ; 24kg of the second

Explanation:

a + b = 60

1.80a + 2.80b = 60 x 2.20

a = 60 - b

1.80 (60-b) + 2.80b = 132

108 - 1.80b + 2.80b = 132

b = 132 - 108

b = 24

a = 60 - 24 = 36