Question

Mrs Dang drove her daughter to school at the average speed of 45 miles per hour. She returned home by the same route at the average speed of 30 miles per hour. If the trip took one half hour, how long did it take to get to school? How far is the school from their home?

Answer 1

Answer: Time it took her to get to the school is 0.6 hours

The distance of the school from their home is 27 miles

Step-by-step explanation:

Mrs Dang drove her daughter to school at the average speed of 45 miles per hour.

Let x miles = distance from the school to their home.

Distance = speed × time

Time = distance / speed

Time used in going to school will be

x/45

She returned home by the same route. This means that distance back home is also x miles.

She returned at an average speed of 30 miles per hour.

Time used in returning home from school will be x/30

x/45

If the trip took one half hour, then the time spent in going to school and the time spent in returning is 1 1/2 hours = 1.5 hours. Therefore

x/30 + x/45 = 1.5

(15x + 10x) /450 = 1.5

15x + 10x = 450 × 1.5 = 675

25x = 675

x = 675/25 = 27

Time it took her to get to the school will be x/45

= 27/45 = 0.6 hours