A car traveled 462 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city. If the car traveled 6 fewer miles per gallon in the city than on the highway, how many miles per gallon did the car travel in the city?
(A) 14
(B) 16
(C) 21
(D) 22
(E) 27
The OA is B.
Please, can any expert explain this PS question for me? I tried to solve it but I can't get the correct answer. I need your help. Thanks.
A car traveled 462 miles per tankful of gasoline on the...
This topic has expert replies
- EconomistGMATTutor
- GMAT Instructor
- Posts: 555
- Joined: Wed Oct 04, 2017 4:18 pm
- Thanked: 180 times
- Followed by:12 members
Hi swerve,A car traveled 462 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city. If the car traveled 6 fewer miles per gallon in the city than on the highway, how many miles per gallon did the car travel in the city?
(A) 14
(B) 16
(C) 21
(D) 22
(E) 27
The OA is B.
Please, can any expert explain this PS question for me? I tried to solve it but I can't get the correct answer. I need your help. Thanks.
Let's take a look at your question.
On Highway, using a tank full of gasoline a car traveled = 462 miles
In city, using a tank full of gasoline a car traveled = 336 miles
Let, On Highway, miles per gallon the car traveled = x miles, then
In city, miles per gallon the car traveled = (x-6) miles
We will be using ratios to solve this problem,
$$\frac{462}{336}=\frac{x}{x-6}$$
$$\frac{231}{168}=\frac{x}{x-6}$$
$$231\left(x-6\right)=168x$$
$$231x-1386=168x$$
$$231x-168x=1386$$
$$63x=1386$$
$$x=\frac{1386}{63}$$
$$x=22$$
We need to find, how many miles per gallon did the car travel in the city?
In city, miles per gallon the car traveled = (x-6) miles
In city, miles per gallon the car traveled = 22-6 = 16 miles
Option B is correct.
Hope it helps.
I am available if you'd like any follow up.
GMAT Prep From The Economist
We offer 70+ point score improvement money back guarantee.
Our average student improves 98 points.
We offer 70+ point score improvement money back guarantee.
Our average student improves 98 points.
- 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
An alternate approach is to PLUG IN THE ANSWERS, which represent the miles per gallon in the city.A car traveled 462 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city. If the car traveled 6 fewer miles per gallon in the city than on the highway, how many miles per gallon did the car travel in the city?
(A) 14
(B) 16
(C) 21
(D) 22
(E) 27
When the correct answer choice is plugged in, the same amount of gas -- in other words, ONE TANKFUL -- will be required to travel 336 miles in the city and 462 miles on the highway.
Since all of the values in the problem are INTEGERS, the correct answer choice must divide evenly into the distance traveled in the city (336).
336 = 2*3*7*8.
Eliminate D (2*11) and E (3*3*3), neither of which divides evenly into 2*3*7*8.
Since on the highway 6 more miles per gallon are traveled, 6 more than the correct answer choice must divide evenly into the distance traveled on the highway (462).
Adding 6 to each of the remaining answer choices, we get:
A: 14+6 = 20 = 2*2*5.
B: 16+6 = 22 = 2*11.
C: 21+6 = 27 = 3*3*3.
Since 462 = 2*3*7*11, only B (2*11) divides evenly into the distance traveled on the highway.
The correct answer is B.
Answer choice B: 16 miles per gallon in the city, 22 miles per gallon on the highway
At a rate of 16 miles per gallon, the amount of gas required to travel 336 miles in the city = 336/16 = 21 gallons.
At a rate of 22 miles per gallon, the amount of gas required to travel 462 miles on the highway = 462/22 = 21 gallons.
Success!
The same amount of gas -- 21 gallons -- is sufficient to travel 336 miles in the city and 462 miles on the highway.
Last edited by GMATGuruNY on Tue Aug 18, 2020 9:40 am, edited 1 time in total.
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: 7247
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
swerve wrote:A car traveled 462 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city. If the car traveled 6 fewer miles per gallon in the city than on the highway, how many miles per gallon did the car travel in the city?
(A) 14
(B) 16
(C) 21
(D) 22
(E) 27
The OA is B.
Please, can any expert explain this PS question for me? I tried to solve it but I can't get the correct answer. I need your help. Thanks.
We can create the proportion in which x = miles per gallon on the highway and (x - 6) = miles per gallon in the city.
(x - 6)/336 = x/462
462x - 2,772 = 336x
126x = 2,772
x = 22
So city mpg = 22 - 6 = 16 mpg.
Alternate Solution:
Let the capacity of the car be n gallons. Then, the car's gas mileage is 462/n miles per gallon on the highway and 336/n miles per gallon in the city. Since we are given that the difference is 6, we have:
462/n - 336/n = 6
126 = 6n
n = 21
Since the capacity of the car is 21 gallons, the care made 336/21 = 16 miles per gallon in the city.
Answer: B
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
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
The car burns a tankful of gas on the highway and a tankful of gas in the city.swerve wrote:A car traveled 462 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city. If the car traveled 6 fewer miles per gallon in the city than on the highway, how many miles per gallon did the car travel in the city?
(A) 14
(B) 16
(C) 21
(D) 22
(E) 27
The OA is B.
Please, can any expert explain this PS question for me? I tried to solve it but I can't get the correct answer. I need your help. Thanks.
So, we can start with this WORD EQUATION: (volume of gas used on the highway) = (volume of gas used in the city)
Key formula: gallons of gas used = (distance traveled)/(rate of miles traveled per gallon)
So, the word equation becomes: (distance traveled on highway)/(highway fuel consumption rate) = (distance traveled in city)/(city fuel consumption rate))
Let x = the rate of fuel consumption in the city (in miles per gallon)
So x+6 = the rate of fuel consumption on highway (in miles per gallon)
The car traveled 462 miles on the highway and 336 miles in the city.
Plug the values into the equation to get to get: 462/x+6 = 336/x
Cross multiply to get: 462x = 336(x + 6)
Expand to get: 462x = 336x + 2016
Subtract 336x from both sides to get: 126x = 2016
Solve: x = 2016/126 = 16
Answer: B
Cheers,
Brent
-
- Junior | Next Rank: 30 Posts
- Posts: 25
- Joined: Tue Jul 16, 2019 4:10 am
its an question of averages , and can be solved by using putting values from answers, But will be lengthy process.
As both in city and highway give same average, we can make a simple equation
Let it travelled : x
462/x = 336/ x-6
336x = 462x- 2772
126x = 2772
x= 22, which is av given on highway
In City , 22-6= 16
As both in city and highway give same average, we can make a simple equation
Let it travelled : x
462/x = 336/ x-6
336x = 462x- 2772
126x = 2772
x= 22, which is av given on highway
In City , 22-6= 16