Author 
Message 
TAGS:

Hide Tags

Senior Manager
Joined: 18 Sep 2009
Posts: 349

At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
23 Sep 2010, 13:37
4
This post received KUDOS
20
This post was BOOKMARKED
Question Stats:
78% (01:06) correct 22% (01:18) wrong based on 1264 sessions
HideShow timer Statistics
At a speed of 50 miles per hour, a certain car uses 1 gallon of gasoline every 30 miles. If the car starts with a full 12 gallon tank of gasoline and travels for 5 hours at 50 miles per hour, the amount of gasoline used would be what fraction of a full tank? A. 3/25 B. 11/36 C. 7/12 D. 2/3 E. 25/36
Official Answer and Stats are available only to registered users. Register/ Login.



Math Expert
Joined: 02 Sep 2009
Posts: 43898

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
23 Sep 2010, 13:39
12
This post received KUDOS
Expert's post
9
This post was BOOKMARKED



Manager
Joined: 04 Aug 2010
Posts: 151

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
24 Sep 2010, 15:04
Gas used = (5 hours)*(50 miles/hour)*(1 gallon/30 miles) = 8+1/3 gallons Portion used = (8+1/3) / 12 = 25/36
Ans E



Intern
Joined: 09 Dec 2010
Posts: 1

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
29 Dec 2010, 04:45
Hi, Could you please advice how to solve below problem
At a speed of 50 miles per hour, a certain car uses 1 gallon of gasoline every 30 miles. If the car starts with a full 12 gallon tank of gasoline and travels for 5 hours. the amount of gasoline used would be what fraction of full tank?
Thank you
Awaiting prompt reply
KD



Manager
Joined: 07 Oct 2010
Posts: 169

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
29 Dec 2010, 06:53
In the given example SPEED is not mentioned with which the car traveled for 5 hrs with 12 gallons in the tank
Therefore, we have to assume that car traveled with the same speed Now we can calculate distance traveled by the car in 5 hrs = D = S*t = 50 * 5 = 250 miles
We know that car travels 30 miles in 1 gallon Therefore gallons of fuel required for 250 miles = 25/3
Hence, fraction of fuel used = 25 /3*12 = 25 / 36
But according to me something is missed out in the question, because, mostly in GMAT answers are not awkward like this.



TOEFL Forum Moderator
Joined: 16 Nov 2010
Posts: 1590
Location: United States (IN)
Concentration: Strategy, Technology

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
26 Apr 2011, 05:44
1
This post received KUDOS
Gasoline used = 250/30 = 25/3 Fraction used = 25/3/12 = 25/36 Answer  E
_________________
Formula of Life > Achievement/Potential = k * Happiness (where k is a constant)
GMAT Club Premium Membership  big benefits and savings



Manager
Joined: 26 Jul 2010
Posts: 100
Location: India
Concentration: Operations, General Management
GMAT 1: 640 Q48 V29 GMAT 2: 670 Q49 V31
WE: Supply Chain Management (Military & Defense)

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
30 Apr 2011, 08:32
ans is e in 5 hours car will travel 250 mile at the rate of 50 miles/hr then gasoline consumed will be \(250/30= 25/3\) => fraction of gasoline used will be (25/3) / 12 === 25/36
_________________
lets start again



Manager
Joined: 06 Jul 2011
Posts: 120

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
30 May 2012, 10:50
1
This post received KUDOS
Round off doesn't work.....250/30 is nearly 8.3 gallons..
Now 8.3/12 is not equal to 8/12(which most people who get wrong answer do) or 2/3 which is a trap and hence wrong answer...I fell in the trap,hence i know :)



Intern
Joined: 17 May 2013
Posts: 47
GMAT Date: 10232013

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
18 Aug 2013, 18:43
1
This post received KUDOS
Speed  50m/h Consumption  1gallon ever 30 miles Given : 12 gallons of fuel at start Expected travel on full Tank  360m/h Actual Travel : 5 * 50 = 250 m/h
Fraction would be : 250/360 = 25/36
Ans: E



Intern
Joined: 30 May 2013
Posts: 3

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
17 Sep 2013, 23:38
2 / 3 is trap answer. you dont need to solve beyond 25 / 8 and get ~8. let 25 / 3 remain an then divide by 12 to get 25 / 36 TomB wrote: At a speed of 50 miles per hour, a certain car uses 1 gallon of gasoline every 30 miles. If the car starts with a full 12 gallon tank of gasoline and travels for 5 hours at 50 miles per hour, the amount of gasoline used would be what fraction of a full tank?
A. 3/25 B. 11/36 C. 7/12 D. 2/3 E. 25/36
I am getting 2/3 .Please explain what am i missing?



Retired Moderator
Joined: 12 Aug 2015
Posts: 2430
GRE 1: 323 Q169 V154

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
04 Dec 2016, 02:11
Great Question Here is what i did in the one => At 50 miles/hour
Distance =250miles so => Used gas => 1/30 *250 => 25/3
Let p be the required fraction. 25/3=p*12 p=25/36
Hence E
_________________
Getting into HOLLYWOOD with an MBA Stone Cold's Mock Tests for GMATQuant(700+)



Intern
Joined: 06 May 2015
Posts: 24

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
05 Dec 2016, 06:49
In 5 hrs the car will travel a distance of 250 miles. 1 gallon every 30 miles equates to 25/3 gallons for 250 miles The amount of gasoline used would be (25/3)/12 = 25/36 gallon
2/3 = 0.6667 25/36 = 0.694 25/3 = 8.3 8.3/12 = 0.691 Hence E is better option than D



Intern
Joined: 07 Mar 2016
Posts: 46

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
11 Apr 2017, 12:34
Kind of an extremely longwinded way to answer this question, but it's how I best visualize it is: car travels 30 miles on 1 gallon. Trip total is 250 miles. 25030=220..first gallon 22030=210..second gallon 21030=190..third gallon 19030=160..fourth gallon 16030=130..fifth gallon 13030=100..sixth gallon 10030=70..seventh gallon 7030=40..eighth gallon Left with 10 gallons which = 1/3 gallon Total of 8.3 gallons over 12 gallon tank. The smallest that can reduce down to is 2/3 so answer choices A,B & C are all out. I then crossmultiplied the remaining two answer choices and got "E". Extremely steporiented but for me it worked. Clockedin at under 2 minutes to solve, though.
_________________
...once and a while you get shown the light, in the strangest of places if you look at it right...



Director
Joined: 17 Dec 2012
Posts: 627
Location: India

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
30 May 2017, 16:26
TomB wrote: At a speed of 50 miles per hour, a certain car uses 1 gallon of gasoline every 30 miles. If the car starts with a full 12 gallon tank of gasoline and travels for 5 hours at 50 miles per hour, the amount of gasoline used would be what fraction of a full tank?
A. 3/25 B. 11/36 C. 7/12 D. 2/3 E. 25/36
I am getting 2/3 .Please explain what am i missing? 1.In 5 hrs the car would have traveled 250 miles. 2. It would have used 250/30 gallons 3. The car started with full tank of 12 gallons 4. Gasoline used as a fraction of full tank is (250/30)/12=25/36
_________________
Srinivasan Vaidyaraman Sravna http://www.sravnatestprep.com
Premium Material Standardized Approaches



Manager
Joined: 20 Jan 2016
Posts: 217

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
03 Aug 2017, 04:42
I fell for the trap answer as well. I rounded off 8.3/12 which is wrong.
I used the following method to solve this:
Distance= speed x time = 50x5=250 miles
Hence, the answer E.
Using ratios, if 30 miles uses 1 gallon, how many gallons will be needed for 250 gallons?
Gallons needed= 250/30 x 1 = 25/3
Therefore, the answer will be (25/3)/12



Intern
Joined: 30 Apr 2014
Posts: 5

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
06 Aug 2017, 13:36
It is important to see that all answer choices are in fraction form and hence do any calcs that way.
1 gallon = 30 miles travel
At a speed of 50 miles/hr for 5 hours , total distance travelled d = \(\frac{50miles}{hr}\)*5hrs = 250 miles
Total gasoline consumed = \(\frac{250}{30}\) = \(\frac{25}{3}\)
Total gasoline consumed as part of the total gasoline available = \(\frac{25}{3}\)*\(\frac{1}{12}\) = \(\frac{25}{36}\)



Intern
Joined: 24 Jan 2017
Posts: 7

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
08 Aug 2017, 02:20
GMAT40 wrote: Speed  50m/h Consumption  1gallon ever 30 miles Given : 12 gallons of fuel at start Expected travel on full Tank  360m/h Actual Travel : 5 * 50 = 250 m/h
Fraction would be : 250/360 = 25/36
Ans: E Thanks a lot! The only option which clarified the last step of dividing by 12. This is the right way of determining the fraction of the done miles vs not done



Target Test Prep Representative
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2016

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
09 Aug 2017, 11:49
TomB wrote: At a speed of 50 miles per hour, a certain car uses 1 gallon of gasoline every 30 miles. If the car starts with a full 12 gallon tank of gasoline and travels for 5 hours at 50 miles per hour, the amount of gasoline used would be what fraction of a full tank?
A. 3/25 B. 11/36 C. 7/12 D. 2/3 E. 25/36 We are given that a certain car has a rate of 30 miles per gallon if its speed is 50 mph. We are next told that the car starts with a 12gallon tank and travels for 5 hours at 50 mph. Since distance = rate x time, we know the car traveled 50 x 5 = 250 miles. We can use the car’s rate and distance traveled to determine how many gallons were used. Gallons used = distance/rate Gallons used = 250/30 = 25/3 We need to determine the amount of gasoline used, as a fraction of a full 12gallon tank. (25/3)/12 = (25/3) x (1/12) = 25/36 Answer: E
_________________
Jeffery Miller
Head of GMAT Instruction
GMAT Quant SelfStudy Course
500+ lessons 3000+ practice problems 800+ HD solutions



Intern
Joined: 15 Jun 2017
Posts: 1

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
27 Nov 2017, 15:11
I think I have an easier solution than what has been posted.
We know that 30mpg x 12 gallons in the tank gives us a range of 360 potential miles.
If we are traveling at 50mph for 5 hrs we thus will use 250 potential miles.
250/360 = 25/36



Intern
Joined: 16 Oct 2017
Posts: 25

Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of [#permalink]
Show Tags
31 Jan 2018, 12:57
Bunuel wrote: At a speed of 50 miles per hour, a certain car uses 1 gallon of gasoline every 30 miles. If the car starts with a full 12 gallon tank of gasoline and travels for 5 hours at 50 miles per hour, the amount of gasoline used would be what fraction of a full tank?
A. 3/25 B. 11/36 C. 7/12 D. 2/3 E. 25/36
In 5 hours at 50 miles per hour car will travel 5*50=250 miles and thus will use 250/30=25/3 gallons of gasoline. Gasoline used/full tank equals to \(\frac{(\frac{25}{3})}{12} =\frac{25}{36}\).
Answer: E. I solved the problem with the approach below and got the correct answer. Did I just get lucky? Will this not work on another similar problem? R x T = D 50mph x 5 hrs = 250 miles 12 gallons x 30 miles = 360 miles (since a car gets 1 gallon of gasoline for every 30 miles). I then just took 250 miles and divided by 360 miles then reduced down to 25/36.




Re: At a speed of 50 miles per hour, a certain car uses 1 gallon of
[#permalink]
31 Jan 2018, 12:57



Go to page
1 2
Next
[ 22 posts ]



