A solution of cough syrup has 15% alcohol. Another solution has 5% alcohol. How many litres of the second solution must be added to 20 litres of the first solution to make a solution of 10% alcohol? Options
A) 10	B) 5	C) 15	D) 20	E) 25
Hence both the types should be added in the ratio of 1 : 1 to obtain the required strength.   Hence 20 litres of first type should be added to the 20 litres of the second type to get the desired solution.   ANSWER:20
<result>D</result>
A solution of cough syrup has 15% alcohol. Another solution has 5% alcohol. How many litres of the second solution must be added to 20 litres of the first solution to make a solution of 10% alcohol?