SOLUTION: a cyclist traveled the first 12 miles of a 30 mile trip at an average speed of 15 miles per hour. Over the first 1/3 of the distance that remained, she averaged 12 miles per hour,

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Question 448914: a cyclist traveled the first 12 miles of a 30 mile trip at an average speed of 15 miles per hour. Over the first 1/3 of the distance that remained, she averaged 12 miles per hour, and over the rest of the trip, she averaged 20 miles per hour, how many hours did it take for cyclist to complete the 30 mile trip ?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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a cyclist traveled the first 12 miles of a 30 mile trip at an average speed of 15 miles per hour.
Over the first 1/3 of the distance that remained, she averaged 12 miles per
hour, and over the rest of the trip, she averaged 20 miles per hour,
how many hours did it take for cyclist to complete the 30 mile trip ?
:
From the info given, how far, how fast?:
1st 12 mi: 15 mph
1%2F3(30-12) = 6: 12 mph
2%2F3(30-12) = 12: 20 mph
:
Write total time equation:
T = 12%2F15 + 6%2F12 + 12%2F20
T = 48%2F60 + 30%2F60 + 36%2F20
T = 114%2F60
t = 1.9 hrs, 1 hr 54 min to complete the trip