A 6-liter solution is 35% alcohol. How many liters of pure alcohol must be added to produce a solution that is 50% alcohol? Choose the correct choice from the following choices.
A) 1.5
B) 1.8
C) 2.1
D) 2.4
E) 2.7

Rationale: "let x be the amount of pure alcohol required . 0.35 ( 6 ) + x = 0.5 ( x + 6 ) 0.5 x = 3 - 2.1 x = 1.8 liters the answer is b ."
Answer: B