SOLUTION: sue drove at a rate of 45 mph from her home to her sister's house. she spent 1 1/2 hours having lunch with her sister. she then drove back home at a rate of 55 mph. the entire trip
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-> SOLUTION: sue drove at a rate of 45 mph from her home to her sister's house. she spent 1 1/2 hours having lunch with her sister. she then drove back home at a rate of 55 mph. the entire trip
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Question 340067: sue drove at a rate of 45 mph from her home to her sister's house. she spent 1 1/2 hours having lunch with her sister. she then drove back home at a rate of 55 mph. the entire trip including lunch took 4 hours. how far does sue live from her sister? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! sue drove at a rate of 45 mph from her home to her sister's house.
she spent 1 1/2 hours having lunch with her sister.
she then drove back home at a rate of 55 mph. the entire trip including lunch took 4 hours.
how far does sue live from her sister?
:
We are only interested in her travel time: 4 - 1.5 = 2.5 hrs
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Let d = distance to sisters house (and back)
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Write a time equation: time = dist/speed + = 2.5
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Multiply by 2475 (that's 45*55) to get rid of the denominators, results
55d + 45d = 2475(2.5)
:
100d = 6187.5
d =
d = 61.875 ~ 62 miles
:
:
Check solution by finding the time each way
62/45 = 1.38 hrs
62/55 = 1.13 hrs
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total: 2.51 hrs, close enough
