SOLUTION: Debbie runs 10km in 1 hour and 40 minutes. in the first half of the journey she runs at 5km/hr. how fast does she travel in the second half of the journey? please explain thouro

Algebra ->  Length-and-distance -> SOLUTION: Debbie runs 10km in 1 hour and 40 minutes. in the first half of the journey she runs at 5km/hr. how fast does she travel in the second half of the journey? please explain thouro      Log On


   

Question 1040955: Debbie runs 10km in 1 hour and 40 minutes. in the first half of the journey she runs at 5km/hr. how fast does she travel in the second half of the journey?
please explain thouroughly, and before sunday if you can!! thank you.
Answer by ikleyn(52806) About Me  (Show Source):
You can put this solution on YOUR website!
.
Debbie runs 10 km in 1 hour and 40 minutes. in the first half of the journey she runs at 5 km/hr.
How fast does she travel in the second half of the journey?
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First half of the distance is 5 km.
Second half of the distance is 5 km, too.

For the first half of the distance she spent 5%2F5 = 1 hour.
Hence, for the second part of the distance she spent 1 hour 40 minutes - 1 hour = 40 minutes.

Thus at the second part Debbie covered  5 km in 40 minutes = 2%2F3 hour.
Then she traveled the second half at the speed of 5%2F%28%282%2F3%29%29 = %285%2A3%29%2F2 = 7.5 km%2Fh.

Answer.  7.5 km%2Fh.
First what you need to do to solve the problem is to read its condition attentively.