SOLUTION: william cycles at 15 miles per hour. he cycles 12 miles from home to school. if he increased his cycling speed by 5 miles per hour, how much faster will he reach school. How do I

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Question 1004440: william cycles at 15 miles per hour. he cycles 12 miles from home to school. if he increased his cycling speed by 5 miles per hour, how much faster will he reach school. How do I get to the answer
Found 2 solutions by josgarithmetic, fractalier:
Answer by josgarithmetic(39628) About Me  (Show Source):
You can put this solution on YOUR website!
RT=D shows the rule for travel rates.

What William does: 15%28miles%2Fhour%29%2At=12%2Amiles, and t is time in HOURS.
Solve for t.

What IF?
%2815%2B5%29%2At%5Bu%5D=12
Solve for t%5Bu%5D.

You must find that according to their values, t%3Et%5Bu%5D.
HOW much is the difference? What is this time difference in MINUTES?



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%2812%2F15-12%2F20%29%2Ahours%2A%2860%2F1%29%28minutes%2Fhour%29

Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
Rate times time equals distance, or rt = d. Thus,
t = d/r = 12/15 = .8 hr = 48 minutes (60 minutes = one hour)
If he travels 5 mph faster, he will now be traveling at 20 mph.
The distance is still 12 miles, but the time is now
t = d/r = 12/20 = .6 hr = 36 minutes
So he saves 12 minutes by traveling faster.