How much of the 80% orange juice mixture did he use?

Question

A college student mixed 3 Liters of 30% orange juice mixture with 80% orange juice mixture to obtain a 60% orange juice mixture.

Answer 1

0.3 * (3) L + 0.8 * (x) L = 0.6 * (3 + x) L

0.3*3 + 0.8*x = 0.6*(3+x)

Solve for x, what does x represent? 

Hint:  Look at the question again.