A 30% alcohol mixture is added to a 50% alcohol mixture to form a 10 litre mixture of 45% alcohol. How much of the 30% mixture was used?
Pick one
A) 1.5 liters
B) 2.5 liters
C) 3.5 liters
D) 4.5 liters
E) 5.5 liters

Rationale: solution a = 50 % solution solution b = 30 % solution 30 % - 45 % = 15 % solution b 50 % - 45 % = 5 % solution a so the ratio is 3 : 1 for 30 % : 50 % solutions 3 / 4 * 10 liter = 7.5 for 30 % solution and 2.5 for 50 % solution . . answer : b
Answer: B