Two vessels P and Q contain 62.5% and 87.5% of alcohol respectively. If 8 litres from vessel P is mixed with 4 litres from vessel Q, the ratio of alcohol and water in the resulting mixture is? Choose the correct choice from the following answers.
A) 17 : 7
B) 18 : 8
C) 19 : 9
D) 19 : 5
E) 19 : 4

Rationale: "quantity of alcohol in vessel p = 62.5 / 100 * 8 = 5 litres quantity of alcohol in vessel q = 87.5 / 100 * 4 = 7 / 2 litres quantity of alcohol in the mixture formed = 5 + 7 / 2 = 17 / 2 = 8.5 litres as 12 litres of mixture is formed , ratio of alcohol and water in the mixture formed = 8.5 : 3.5 = 17 : 7 . answer : a"
Answer: A