At elm elementary school for every 5 students who walk to school there are 7 students who take the bus. if 420 students attend elm elementary school how many of them walk to school? tell me how you got the answer and will mark brainliest

Afamily has two cars. the first car has a fuel efficiency of 25 miles per gallon of gas and the second has a fuel efficiency of 15 miles per gallon of gas. during one particular week, the two cars went a combined total of 1025 miles, for a total gas consumption of 55 gallons. how many gallons were consumed by each of the two cars that week?