A 6 litre sol is 25% alcohol .How many litres of pure alcohol must be added to produce a sol that is 50% alcohol ?	Choose the correct choice from the following answers
A) a . 0.6 B) b . 1 C) c . 2.1 D) d . 3 E) e . 5.4

Rationale: "25 % of 6 = 1.5 50 % of 6 = 3 shortage is 1.5 so we need to have 1.5 / 50 % to get 50 % alcohol content . = 3 d"
Answer: D