Tell your mom blow me

If x varies directly as y, and x = 7.5 when y = 10, find x when y = 4

While on a train trip, marsha noticed that there were 35 people in her train car. after the next stop, there were only 21 people in her car. if p represents the percent decrease in the number of people in marsha's train car, what is p?

Decide whether the rates are equivalent. 96 miles on 4 gallons, 380 miles on 15 gallons