Question

Jonathan forgot his math homework on the kitchen table and left for school without it. He biked at the speed of 15 mph. His mother saw the homework when he was already 1 mile from home, and started chasing him. She drove at a speed of 25 mph and caught him at the school entrance. How far is the school from Jonathan's home?

Answer 1

2.5 miles

Explanation:

We know that: time = distance/speed

Now, if the distance of the school from Jonathan's home is y.

At speed of 15 mph, Jonathans time is; time = y/15 hours

At 25 mph, his mother's time was;

time = y/25 hours

We are told that Jonathan was 1 mile from home when he saw his mother.

Thus means that difference in time is;

Time difference = 1/15 hours

Thus;

y/15 hours - y/25 hours = 1/15 hours

Multiply through by 75 to get;

5y - 3y = 5

2y = 5

y = 5/2

y = 2.5 miles