The line in the xyxyx, y-plane above represents the relationship between the height h(x)h(x)h, left parenthesis, x, right parenthesis, in feet, and the base diameter xxx, in feet, for cylindrical Doric columns in ancient Greek architecture. How much greater is the height of a Doric column that has a base diameter of 555 feet than the height of a Doric column that has a base diameter of 222 feet?

Raul has one solution that is 20% acid by volume and one solution that is 50% acid by volume. he plans to mix together some of each solution to create 30 milliliters of a solution that is 40% acid by volume. how many milliliters of the 20% acid solution should raul use to create the 40% acid solution? can someone explain this to me? i know that the answer is 10 milliliters, but i don't know how to get it.