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P6: Speed - Common Distance

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#4602

P6: Speed - Common Distance 1 Year, 5 Months ago	Karma: -1
John usually takes 10 minutes to walk from his house to his school. if he runs, he can reach his school 4 minutes earlier. His running speed is 52 m/min faster than his walking speed. Find the distance between his school and his house.

hajee

Last Edit: 2010/08/31 23:07 By Chris.

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#4603

Re:P6: Speed Pb 1 Year, 5 Months ago

Karma: 138

John usually takes 10 minutes to walk from his house to his school. If he runs, he can reach his school 4 minutes earlier. His running speed is 52 m/min faster than his walking speed.
Find the distance between his school and his house.

You can use Speed with a Common Distance for this question.

Common Distance
Ratio of Time
W : R
10 : 6
5 : 3

Ratio of Speed is inversely proportional to the Ratio of Time

Ratio of Speed
W : R
3 : 5

Difference is 2units
2units --> 52m/min

Edited - divide by 2

1unit --> 26m/min
Speed of walking --> 3units
3 x 26m/min --> 78m/min

It took him 10 min
--> 10min x 78m/min = 780m

Chris Rogers

Last Edit: 2010/09/09 10:03 By Chris.

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#4604

Re:P6: Speed Pb 1 Year, 5 Months ago	Karma: -1
Thank you chris

hajee

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#4703

Re:P6: Speed Pb 1 Year, 5 Months ago	Karma: 32
Chris, You have an aversion towards dividing by 2 Must have been your twin brother who wanted to get half of everything of yours 2units --> 52m/min 1 unit --> 52m/min/2 = 26 m/min Speed of walking --> 3units 3 x 26m/min --> 78 m/min It took him 10 min --> 10min x 78m/min = 780m

Reynold Tan

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#4704

Re:P6: Speed Pb 1 Year, 5 Months ago	Karma: 138
How did you know! Perhaps I can blame it on my new set of contact lens - only 1/2 is working.... Thanks

Chris Rogers

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