Last visit was: 19 Nov 2025, 09:29 It is currently 19 Nov 2025, 09:29
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Nov 2025
Posts: 105,389
Own Kudos:
778,287
 [1]
Given Kudos: 99,977
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,389
Kudos: 778,287
 [1]
A certain car travels 18 miles per gallon of gas on city streets and 3 07 Feb 2020, 06:22
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

35% (medium)

Question Stats:

74% (01:51) correct 26% (01:50) wrong based on 89 sessions

History

Date
Time
Result
Not Attempted Yet
A certain car travels 18 miles per gallon of gas on city streets and 30 miles per gallon of gas on highway. Damaris drives the car to work during the week and travels on city streets and on the highway. She drives the car on the highway more miles than she drives on city streets. How many miles does Damaris drive to work on the highway?

(1) Damaris drives a total of 26 miles.

(2) The car Damaris drives uses 1 gallon of gas to get to work.
ShowHide Answer
Official Answer
C
User avatar
Kinshook
User avatar
Major Poster
Joined: 03 Jun 2019
Last visit: 19 Nov 2025
Posts: 5,794
Own Kudos:
5,509
 [2]
Given Kudos: 161
Location: India
Schools: HBS '26 CBS '26 Wharton '26
GMAT 1: 690 Q50 V34
WE:Engineering (Transportation)
Products:
My Reviews
Schools: HBS '26 CBS '26 Wharton '26
GMAT 1: 690 Q50 V34
Posts: 5,794
Kudos: 5,509
 [2]
A certain car travels 18 miles per gallon of gas on city streets and 3 11 Feb 2020, 04:10
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
A certain car travels 18 miles per gallon of gas on city streets and 30 miles per gallon of gas on highway. Damaris drives the car to work during the week and travels on city streets and on the highway. She drives the car on the highway more miles than she drives on city streets. How many miles does Damaris drive to work on the highway?

(1) Damaris drives a total of 26 miles.

(2) The car Damaris drives uses 1 gallon of gas to get to work.
Show more

Given:
1. A certain car travels 18 miles per gallon of gas on city streets and 30 miles per gallon of gas on highway.
2, Damaris drives the car to work during the week and travels on city streets and on the highway.
3. She drives the car on the highway more miles than she drives on city streets.

Asked: How many miles does Damaris drive to work on the highway?

(1) Damaris drives a total of 26 miles.
It may be inferred from information above that Damaris drives more than 13 miles on the highway.
But number of miles driven on highway can not be determined.
NOT SUFFICIENT

(2) The car Damaris drives uses 1 gallon of gas to get to work.
Damaris drive minimum of 18 miles and maximum of 30 miles on her way to work.
But number of miles driven on highway can not be determined.
NOT SUFFICIENT

(1) + 2)
(1) Damaris drives a total of 26 miles.
(2) The car Damaris drives uses 1 gallon of gas to get to work.
Damaris on average drives @ 26 miles/gallon of gas
Let portion of her highway travel be x
18(1-x) + 30x = 26
18 + 12x = 26
x= 8/12 = 2/3
Damaris drives on highway = 26*2/3 = 52/3 = 17.33 miles
SUFFICIENT

IMO C
User avatar
Vinit800HBS
User avatar
Joined: 29 Dec 2018
Last visit: 18 Nov 2025
Posts: 91
Own Kudos:
237
 [2]
Given Kudos: 195
Location: India
Schools: HBS '22 Wharton '22 Stanford '22
GRE 1: Q170 V163
Expert
Expert reply
Schools: HBS '22 Wharton '22 Stanford '22
GRE 1: Q170 V163
Posts: 91
Kudos: 237
 [2]
A certain car travels 18 miles per gallon of gas on city streets and 3 11 Feb 2020, 04:27
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Let the number of miles travelled in City and that on Highway be C and H respectively.

Given,

H>C

1 gallon on Highway helps travel 30 miles
1 gallon in City helps travel 18 miles.

Thus,

For 1 mile on Highway, gas required is 1/30th of a gallon

For 1 mile in City, gas required is 1/18th of a gallon

Objective: To find number of miles traveled on Highway.

Statement 1:
Total miles traveled is 26
Thus,
H+C = 26

Multiple combinations are possible.
Hence, not sufficient.

Eliminate A and D

Statement 2:

Total gas used is 1 gallon

So,
H/30 + C/18 = 1
I.e. 3H + 5C = 90
Now, again we have multiple combinations possible as we know that H and C can be fractions also.

Hence, statement 2 is also not sufficient.

Eliminate B

Together,

We have
H+C = 26
3H + 5C = 90

Solving for H and C, we get
H = 20 and C = 6

Hence, C should be the answer.

Quick Verification:

We have H>C
For 20 miles on highway, 20/30 = 2/3rd of a gallon is used
For 6 miles in City, 6/18 = 1/3rd of a gallon is used.

Total gas used is 1 gallon.

Everything checks out properly.


Feel free to tag me for any further clarification.

Posted from my mobile device
User avatar
GMATWhizTeam
User avatar
GMATWhiz Representative
Joined: 07 May 2019
Last visit: 14 Oct 2025
Posts: 3,380
Own Kudos:
2,141
 [2]
Given Kudos: 69
Location: India
GMAT 1: 740 Q50 V41
GMAT 2: 760 Q51 V40
Expert
Expert reply
GMAT 2: 760 Q51 V40
Posts: 3,380
Kudos: 2,141
 [2]
A certain car travels 18 miles per gallon of gas on city streets and 3 11 Feb 2020, 06:05
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
A certain car travels 18 miles per gallon of gas on city streets and 30 miles per gallon of gas on highway. Damaris drives the car to work during the week and travels on city streets and on the highway. She drives the car on the highway more miles than she drives on city streets. How many miles does Damaris drive to work on the highway?

(1) Damaris drives a total of 26 miles.

(2) The car Damaris drives uses 1 gallon of gas to get to work.
Show more

Solution


Step 1: Analyse Question Stem


    • The car can travel 18 miles per gallon of gas on the city street.
      o So, gallons of gas required to drive 1 mile on City street \(= \frac{1}{18}\)

    • Also, the car can travel 30 miles per gallon of gas on highway.
      o So, gallons of gas required to drive 1 mile on the highway \(= \frac{1}{30}\)
    • Let us assume that Damaris drives c miles on the city street and h miles on the highway to reach work.
    • \(h > c\)
We need to find the value of h.

Step 2: Analyse Statements Independently (And eliminate options) – AD/BCE


Statement 1: Damaris drives a total of 26 miles.
    • According to this statement: \(c+h =26\)
      o since \(h > c\), from above equation we get
         \(h+h > 26\)
         Or,\( h> 13 \)
         However, we cannot determine the exact value of h.
Hence, statement 1 is not sufficient and we can eliminate answer options A and D
Statement 2: The car Damaris drives uses 1 gallon of gas to get to work.
    • According to this statement:\(c*\frac{1}{18} + h*\frac{1}{30} = 1\)
      o or, \(\frac{5c + 3h }{90} = 1\)
      o or, \(5c + 3h = 90\)
         Since \(h > c\), we can write
         \(5h +3h > 90\)
         \(h > 11.25 \)
We know that h > 11.25 but we cannot determine the exact value of h from this statement alone.
Hence, statement 2 is also not sufficient and we can eliminate answer B.

Step 3: Analyse Statements by combining.


    • From statement 1: \(c + h = 26\)
    • From statement 2: \(5c + 3h = 90\)
    • On combining both, we have two equations and two variables, so we can solve to get the value of h.
Thus, the correct answer is Option C.
User avatar
BhishmaNaidu99
User avatar
Joined: 22 Sep 2018
Last visit: 29 Jun 2020
Posts: 70
Own Kudos:
90
 [1]
Given Kudos: 95
Schools: EDHEC MiM "22 (A)
Schools: EDHEC MiM "22 (A)
Posts: 70
Kudos: 90
 [1]
A certain car travels 18 miles per gallon of gas on city streets and 3 13 Feb 2020, 20:47
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
IMO C
Car on highway gives 30 miles per gallon, and on street gives 18 miles per gallon

Statement 1
GIVES H.MIles + S.Miles = 26
We cannot say directly from this the number of miles from each, INSUFFICIENT

Statement 2
Given total gallons used = 1 gallon .
we don't know any ratio of each one to find the answer from this , so INSUFFICIENT

Statment 1+2 ,

Let Car travels x miles on street , fuel used for x miles will, x/18 gallos ,
Remaining 26-x miles on high way, fuel used for 26-x miles will be , 26-x/30 gallon

Given total gallons = 1 , x/18 + 26-x/30 = 1 ,
30*18 + (26-x)*18 = 18*30,
x = 6 miles , and high way miles = 26-x = 20. SUFFICIENT
User avatar
HC1993
User avatar
Joined: 25 Aug 2020
Last visit: 11 Dec 2022
Posts: 21
Own Kudos:
3
Given Kudos: 10
WE:Account Management (Advertising and PR)
Posts: 21
Kudos: 3
A certain car travels 18 miles per gallon of gas on city streets and 3 18 Sep 2022, 04:00
Kudos
Add Kudos
Bookmarks
Bookmark this Post
rate(city) = 18mpg, rate (highway) = 30 mpg

rate = miles/gallon => r = m/g

miles(total) = miles (c) + miles (h)
r*g (t)= r*g(c) + r*g(h)

1. total miles is 26. But we dont know the miles of c and h, hence NS
2. Total gallon used for work = 1gallon NS

1 & 2

We get the total rate as 26 miles per gallon
and g(c) + g(h) = 1

Put in the above equation and hence Sufficient
Moderators:
Bunuel
Math Expert
105389 posts
kingbucky
496 posts