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
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