Explain one way in which the historical situation of the late nineteenth century might have affected the vision of africa’s future outlined by the author in the third paragraph

What is the missing step in this proof? scroll down to see the entire proof. u

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.

What can cause a person in altered state to see colors and hear sounds