A certain mule travels at 2/3 the speed of a certain horse. If it takes the horse 6 hours to travel 20 miles, how many hours will the trip take the mule ?
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I am having trouble with distance calculation (1)
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candygal79
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Horse = H
Mule = 2/3H
Horse
T = 6hr
D = 20 miles
S = 20/6 = 10/3
Speed of Mule = 2/3 * 10/3 = 20/9
Total Time = 20/(20/9) = 9
Mule = 2/3H
Horse
T = 6hr
D = 20 miles
S = 20/6 = 10/3
Speed of Mule = 2/3 * 10/3 = 20/9
Total Time = 20/(20/9) = 9
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Hi candygal79,
This question is ultimately about how a difference in speeds will affect a difference in time. The distance could be ANY distance and the answer will be the same.
To that end, here's a slightly simpler version of this question, using the same data for everything but the distance (which we'll set at 18 miles)
Horse: takes 6 hours to travel 18 miles.
D = R x T
18 = R x 6
Rate = 3mph
Mule: travels 2/3 the speed of the horse = 2/3 of 3 = 2mph
D = R x T
18 = 2 x T
Time = 9 hours
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
This question is ultimately about how a difference in speeds will affect a difference in time. The distance could be ANY distance and the answer will be the same.
To that end, here's a slightly simpler version of this question, using the same data for everything but the distance (which we'll set at 18 miles)
Horse: takes 6 hours to travel 18 miles.
D = R x T
18 = R x 6
Rate = 3mph
Mule: travels 2/3 the speed of the horse = 2/3 of 3 = 2mph
D = R x T
18 = 2 x T
Time = 9 hours
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
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GMATGuruNY
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TIME AND RATE are RECIPROCALS.candygal79 wrote:A certain mule travels at 2/3 the speed of a certain horse. If it takes the horse 6 hours to travel 20 miles, how many hours will the trip take the mule ?
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Since the mule travels at 2/3 the horse's speed, the mule will require 3/2 the horse's time:
(3/2)(6 hours) = 9 hours.
The correct answer is C.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
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