SOLUTION: Erynn walked at a constant rate for 2 hours and bicycled at three times that rate for 1/3 hours. She traveled 12km in all. What was her walking rate?

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Question 100321: Erynn walked at a constant rate for 2 hours and bicycled at three times that rate for 1/3 hours. She traveled 12km in all. What was her walking rate?












Answer by TP(29) About Me  (Show Source):
You can put this solution on YOUR website!
Let the walking rate be x(km/h).
This means that after 1 hour she has walked x km.
So after 2 hours she will have walked 2x km.
We are told that she then cycles at three times her walking rate.
This means that her cycling rate =3*x=3x(km/h).
But we are told that she only cycles for 1/3 of an hour and so her cycling distance is 1/3 of 3x km. which is 1x or x km.
So she walks 2x km and cycles x km,giving a total travelling distance of 3x km.
But we are told that the total distance travelled is 12km.
Hence 3x=12.
Now share each side of this equation by 3 and we get:
x=4.
So her walking rate is 4km/h.ANS
(NB. In English English we usually say "cycled" rather than "bicycled" and we spell the US "traveled" as "travelled"!).