Question 500524
50% concentration is the desired answer.
You computed x = # quarts (out of 4 total) of OJ in the final.
Actually, your "x" changed meaning in midstream.
Better continuation of what you wrote:
2*1 + 2*0 = x quantity * y concentration
x = 2+2 (the total volume)
2 = 4 y
y = 1/2 concentration.