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Hafsa Kamous
- Newbie | Next Rank: 10 Posts
- Posts: 1
- Joined: Mon Apr 19, 2010 5:02 am
Hi everybody,
Can you please help me understand this problem:
Scott starts jogging from point X to point Y. A half-hour later his friend Garrett who jogs 1
mile per hour slower than twice Scott's rate starts from the same point and follows the same
path. If Garrett overtakes Scott in 2 hours, how many miles will Garrett have covered?
(A) 2 1/5
(B) 3 1/3
(C) 4
(D) 6
(E) 6 2/3
The answer is :
Following Guideline 1, we let r = Scott's rate. Then 2r - 1 = Garrett's rate. Turning to Guideline 2, we look for two quantities that are equal to each other. When Garrett overtakes Scott, they will have traveled the same distance. Now, from the formula D= R * T , Scott's distance is D= r * 2 1/2 (I don't understand this formula)
and Garrett's distance is D = (2r - 1)2 = 4r - 2
Setting these expressions equal to each other gives 4r * 2 = r * 2 1/2
Solving this equation for r gives r = 4/3
Hence, Garrett will have traveled D= 4r * 2 = 4 (4/3 - 2 = 3 1/3 miles.
The answer is (B).
Can you please help me understand this problem:
Scott starts jogging from point X to point Y. A half-hour later his friend Garrett who jogs 1
mile per hour slower than twice Scott's rate starts from the same point and follows the same
path. If Garrett overtakes Scott in 2 hours, how many miles will Garrett have covered?
(A) 2 1/5
(B) 3 1/3
(C) 4
(D) 6
(E) 6 2/3
The answer is :
Following Guideline 1, we let r = Scott's rate. Then 2r - 1 = Garrett's rate. Turning to Guideline 2, we look for two quantities that are equal to each other. When Garrett overtakes Scott, they will have traveled the same distance. Now, from the formula D= R * T , Scott's distance is D= r * 2 1/2 (I don't understand this formula)
and Garrett's distance is D = (2r - 1)2 = 4r - 2
Setting these expressions equal to each other gives 4r * 2 = r * 2 1/2
Solving this equation for r gives r = 4/3
Hence, Garrett will have traveled D= 4r * 2 = 4 (4/3 - 2 = 3 1/3 miles.
The answer is (B).
