Royal fruit company

Question

The Royal Fruit Company produces two types of fruit drinks. The first type is 60%

 pure fruit juice, and the second type is 85% pure fruit juice. The company is attempting to produce a fruit drink that contains 80% pure fruit juice. How many pints of each of the two existing types of drink must be used to make 80 pints of a mixture that is 80% pure fruit juice?

Answer 1

0.6x + 0.85(80 - x) = 0.8(80)

0.6x + 68 - 0.85x = 64

-0.25x = -4

x = 16

Answer 2

85x + 60(80-x) = 80(80)

25x = 80(80)-60(80) = 20(80)

x = 20(80)/25 = 4(80)/5= 4(16) = 64

x=64 pints of 85% mixed with

80-64 = 16 pints of 60%

to get

80 pints of 80%

a check on the answers:

85-80=5

80-60= 20

20/5 = 4

64/16 = 4

the one closer to what you want gets more

the one further away gets less

85% is closer to 80%, 4 times closer

so you want 4 times more

64 is 4 times 16

(if you're diabetic, you may want to avoid them all. sugar can be a real killer,

sometimes, or a real life saver, if the blood sugar level is too low)