Solution X is 10 percent alcohol by volume, and solution Y is 30 percent alcohol by volume.

Solution X is 10 percent alcohol by volume, and solution Y is 30 percent alcohol by volume. How many milliliters of solution Y must be added to 300 milliliters of solution X to create a solution that is 15 percent alcohol by volume?

Quiz

Answer/Solution

100

Steps/Work

15% is 5%-points higher than 10% but 15%-points lower than 30%.
Thus there should be 3 parts of solution X for 1 part of solution Y.
We should add 100 ml of solution Y.
The answer is B.