A 6 litre sol is 40% alcohol .How many litres of pure alcohol must be added to produce a sol that is 50% alcohol ?  Options.
A) a . 0.6 B) b . 1.2 C) c . 2.1 D) d . 3 E) e . 5.4

Rationale: "40 % of 6 = 2.4 50 % of 6 = 3 shortage is 0.6 so we need to have 0.6 / 50 % to get 50 % alcohol content . = 1.2 b"
Answer: B