A cleaning crew always uses a 10% disinfectant solution on very delicate surfaces. But today, the crew only has a 50% disinfectant solution. If the crew needs 25 liters of 10% solution, how many liters of water and how many liters of the 50% disinfectant should they mix?

The tuition costs, c, for a local community college are modeled by c(h) = 250 + 200h, where h represents the number of credit hours taken. the local state university has tuition costs, s, modeled by the function s(h) = 300 + 180h. how many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

The amount spent on food and drink by 20 customers is shown below what is the modal amount spent and the median? 40 25 8 36 18 15 24 27 43 9 12 19 22 34 31 20 26 19 17 28

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.