After driving to a riverfront parking lot, Bob plans to run south along the river, turn around, and return to the parking lot, running north along the same path. After running 3.25 miles south, he decides to run for only 50 minutes more. If Bob runs at a constant rate of 8 minutes per mile, how many miles farther south can he run and still be able to return to the parking lot in 50 minutes?
(A) 1.5
(B) 2.25
(C) 3.0
(D) 3.25
(E) 4.75
OAA
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
Bob plans to run south along the river
This topic has expert replies
-
GMATGuruNY
- GMAT Instructor
- Posts: 15539
- Joined: Tue May 25, 2010 12:04 pm
- Location: New York, NY
- Thanked: 13060 times
- Followed by:1906 members
- GMAT Score:790
In the solution below, the units in red CANCEL OUT.After driving to a riverfront parking lot, Bob plans to
run south along the river, turn around, and return to
the parking lot, running north along the same path.
After running 3.25 miles south, he decides to run for
only 50 minutes more. If Bob runs at a constant rate
of 8 minutes per mile, how many miles farther south
can he run and still be able to return to the parking lot
in 50 minutes?
(A) 1.5
(B) 2.25
(C) 3.0
(D) 3.25
(E) 4.75
Time to travel 3.25 miles at a rate of 8 minutes per mile = 3.25 miles * (8 minutes)/(1 mile) = (3.25)(8) minutes = 26 minutes.
Since Bob travels for 50 more minutes -- for a total of 76 minutes -- the total distance traveled = 76 minutes * (1 mile/8 minutes) = 76/8 miles = 19/2 miles.
Since half the total distance is traveled in each direction, the total distance traveled south = (19/2) * (1/2) = 19/4 miles.
Since 3.25 miles south have already been traveled, the additional distance traveled south = 19/4 - 3.25 = 19/4 - 13/4 = 6/4 = 1.5 miles.
The correct answer is A.
To use r*t = d -- where r is in terms of MILES PER MINUTE -- we could proceed as follows:
d = 3.25 miles.
r = 1 mile per 8 minutes = 1/8 mile per minute.
Since t = d/r, we get:
t = (3.25)/(1/8) = (3.25)(8) = 26 minutes.
Since Bob travels for an additional 50 minutes -- for a total of 76 minutes -- at a rate of 1/8 mile per minute, we get:
Total distance = r*t = 1/8 * 76 = 19/2 miles.
From here, we could proceed as in my solution above.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
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].
Student Review #1
Student Review #2
Student Review #3
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].
Student Review #1
Student Review #2
Student Review #3
GMAT/MBA Expert
-
Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7243
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
We are given that Bob plans to run south along the river, turn around, and return to where he started.rsarashi wrote:After driving to a riverfront parking lot, Bob plans to run south along the river, turn around, and return to the parking lot, running north along the same path. After running 3.25 miles south, he decides to run for only 50 minutes more. If Bob runs at a constant rate of 8 minutes per mile, how many miles farther south can he run and still be able to return to the parking lot in 50 minutes?
(A) 1.5
(B) 2.25
(C) 3.0
(D) 3.25
(E) 4.75
OAA
We know that his run south (from the parking lot) and his run north (back to the parking lot) are equal in distance. We will use this information later in the solution.
We are also given that Bob's rate is 8 minutes per mile, or, in other words, (since Rate = Distance/Time) his rate is 1 mile per 8 minutes or 1/8.
We are told that Bob has already run 3.25 miles south, and he wants to run for 50 minutes more. Thus, we calculate how far Bob will go in the remaining 50 minutes.
Distance = Rate x Time
Distance = 1/8 x 50
Distance = 50/8 = 25/4 = 6.25 miles
Thus, we know that Bob's total running distance will be 6.25 + 3.25 = 9.5 miles. Because we know the distance is the same both ways, we know that each leg of his trip is 9.5/2 = 4.75 miles. Since Bob has already run 3.25 miles south, he can continue to run south for 4.75 - 3.25 = 1.5 miles more. At that point, he will have to turn around and head back north to the parking lot.
Answer: A
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews
