Question 1195942: Darren drives to school in rush hour traffic and averages 22mph. He returns home in mid-afternoon when there is less traffic and averages 44mph. What is the distance between his home and school if the total traveling time is 1hr 30min?
Found 3 solutions by ikleyn, josgarithmetic, greenestamps:
Answer by ikleyn(53763)   (Show Source):
You can put this solution on YOUR website! .
Darren drives to school in rush hour traffic and averages 22mph.
He returns home in mid-afternoon when there is less traffic and averages 44mph.
What is the distance between his home and school if the total traveling time is 1hr 30min?
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Notice that 44 mph is twice as fast as 22 mph.
It means, and you can get it intuitively, that one third of the total travel time,
which is 1 hour and 30 minutes, is spend with the rate of 44 mph.
Again, the travel time with the rate of 44 mph was 30 minutes, or half an hour.
It implies that one way distance to the school is 22 miles. ANSWER
Solved (mentally).
Answer by josgarithmetic(39799)  (Show Source):
Answer by greenestamps(13334)  (Show Source):
You can put this solution on YOUR website!
The distances going and returning are the same; and the return trip is at a speed twice the speed of the trip to school.
That means the amount of time for the return trip is half the time for the trip there.
Then, since the total time was 1 hour 30 minutes, he spent 1 hour at 22mph going and a half hour at 44mph returning.
Use either time and speed (rate) to find that the distance (rate times time) is 22 miles.
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