Question

Jane's sweet shop mixes candy worth 80 cents per pound with candy worth 2 dollars per pound to make 20 pounds of a mixture worth 1.60 per pound. How many pounds of each kind of candy does the store use?

Answer 1

80 a +200 b = 160 *20 = 3200
and
a + b = 20 so b=20-a

80 a + 200(20-a) = 3200

80 a + 4000 -200 a = 3200

120 a = 800
12 a = 80
a = 6 2/3 pounds
so b = 20-a = 13 1/3 pounds