Can someone please answer this question? Someone answered and they deleted their answer, so I need someone else to help me! Please do not delete your answer, steal the points, or send links, I really need some help!

How many quarts of a 50% solution of acid must be added to 20 quarts of a 20% solution of acid in order to get a 40% solution of acid?

Three runners competed in a race data were collected at each mile mark for each runner if the runner ran at a constant pace the data would be linear

Harold wrote this equation to model the level of water in a pool over time. the variable x represents time in hours. f(x) = 3,500 - 225x which statements about the situation are true? check all that apply. the water level is rising. the water level is falling. the initial level of water in the pool was 3,500 units. the initial level of water in the pool was 225 units. the pool was empty after 14 hours. the water was 2,600 units high after 4 hours.