How much Of a 90% orange juice drink must be mixed with 12 gallons of a 30% orange juice drink to obtain a mixture that is 50% orange juice

Question

The amount of 90% orange juice drink is blank gallons

Answer 1

The OJ concentration is

0.9 X + 12*0.3 = 0.5(x+12)

0.9x + 3.6 = 0.5x + 6

0.4x + 3.6 = 6

0.4x = 2.4

4x = 24

x = 6