Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.
close

It is currently 20 Jul 2019, 15:16
Register
GMAT Club Tests
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

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
CLICK HERE TO HIDE/SHOW EVENTS

The amount of coal a train burns each mile is directly propo

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
  Sort by Date Sort by Kudos  
Search for:
 
Print view
First unread post
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Intern
Intern
avatar
Joined: 04 May 2010
Posts: 1
The amount of coal a train burns each mile is directly propo  [#permalink]

Show Tags

New post Updated on: 26 May 2014, 02:11
1
9
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

74% (01:25) correct 26% (01:27) wrong based on 371 sessions

HideShow timer Statistics


The amount of coal a train burns each mile is directly proportional to the speed at which it travels. How much coal will it burn on this particular 60 mile trip?

(1) On a previous trip, the train burned 100 pounds of coal on a 60 mile trip at 60 miles per hour
(2) On this particular trip, the train is travelling at a speed of 30 miles per hour.


Spoiler: ::
(isn't the second statement irrelevant? because once you know the value of the constant of fuel burned per speed (directly proportional to one another so it doesnt change in value), you know the distance, and since rate and time are inversely proportional to one another, doesn't the actual rate become unimportant? The book answer to this question was C, but I don't understand why its not A...)
Spoiler: OA

Originally posted by gmatmathguy123 on 04 May 2010, 06:13.
Last edited by Bunuel on 26 May 2014, 02:11, edited 2 times in total.
OA added
Manager
Manager
avatar
Joined: 24 Jul 2009
Posts: 225
Re: DS question...  [#permalink]

Show Tags

New post 04 May 2010, 07:29
1
gmatmathguy123 wrote:
The amount of coal a train burns each mile is directly proportional to the speed at which it travels. How much coal will it burn on this particular 60 mile trip?
(1) On a previous trip, the train burned 100 pounds of coal on a 60 mile trip at 60 mph
(2) On this particular trip, the train is traveling at a speed of 30mph



(isn't the second statement irrelevant? because once you know the value of the constant of fuel burned per speed (directly proportional to one another so it doesnt change in value), you know the distance, and since rate and time are inversely proportional to one another, doesn't the actual rate become unimportant? The book answer to this question was C, but I don't understand why its not A...)


Given C = k*M, where C is amount of coal/per mile, k proportionality constant, and M speed of the train.
So, We have to find C and distance is given as 60
To find C, we need the value of k and the speed at which present journey is made.

Statement 1:
(100/60) = k*(60).. So k is 1/36, (Old journey..!!)
Now we have k..
DO we know the value of speed during the present journey..NO. INSUFFICIENT

Statement 2:
C = k* (60/30)
We have the speed of the present journey. But don't have the value of K.INSUFFICIENT

Statement 2 and Statement 1:
For present journey, we have K and the speed.. Answer C.
Manager
Manager
avatar
Joined: 16 Feb 2010
Posts: 128
Re: DS question...  [#permalink]

Show Tags

New post 16 May 2010, 12:51
since the amount of coal the train burns is directly proportional to speed so the train burns a diffrent total amount of coal on the journey, more speed more amout of coal would be burnt, to get the fixed amount there must be a fixed speed which is provided by statement B , hence C is the right answer.
Intern
Intern
avatar
Joined: 21 Mar 2010
Posts: 14
GMAT ToolKit User
Re: DS question...  [#permalink]

Show Tags

New post 17 May 2010, 22:31
The amount of coal a train burns each mile is directly proportional to the speed at which it travels. How much coal will it burn on this particular 60 mile trip?
(1) On a previous trip, the train burned 100 pounds of coal on a 60 mile trip at 60 mph
(2) On this particular trip, the train is traveling at a speed of 30mph


We must know the speed of the train on this particular 60 mile trip. Second statement provides speed of 30mph.
Furthermore, We must know the constant associated with the proportion. Obviously, first statement helps to find the constant.
Therefore, We need both of the statements to answer the question.
Hence, answer is C
Intern
Intern
avatar
Joined: 11 Aug 2013
Posts: 25
Location: India
Concentration: Finance, General Management
GMAT 1: 620 Q47 V28
GPA: 3.23
WE: Information Technology (Investment Banking)
Re: The amount of coal a train burns each mile is directly propo  [#permalink]

Show Tags

New post 03 Jun 2014, 09:24
To answer the question we require to know the value of 2 parameters
1. Speed of the train
2. Rate of consumption of the coal.

From Option(1) we can only get rate of consumption of the coal. Speed of the train is unknown. Hence INSUFFICIENT
From Option(2) We only have the speed of the train. rate of consumption of coal is Unkown. Again INSUFFICIENT

Combining (1) and(2) we clearly get both the parameters

Hope This Helps
_________________
Thanks
Sindbad
----------------
Click +1 Kudos if my post helped...
Signature Read More
Intern
Intern
avatar
Joined: 05 Jun 2016
Posts: 1
Re: The amount of coal a train burns each mile is directly propo  [#permalink]

Show Tags

New post 18 Jul 2016, 00:32
Sindbad wrote:
To answer the question we require to know the value of 2 parameters
1. Speed of the train
2. Rate of consumption of the coal.

From Option(1) we can only get rate of consumption of the coal. Speed of the train is unknown. Hence INSUFFICIENT
From Option(2) We only have the speed of the train. rate of consumption of coal is Unkown. Again INSUFFICIENT

Combining (1) and(2) we clearly get both the parameters

Hope This Helps

People implied here that => if y is proportional to x, it means y = mx .
But its actually y = mx +c . Here is the special case since if speed is 0, we are taking special condition and saying fuel consumed will be 0.
If it was anything other than speed and coal consumption question, i think that time answer should have been E.
But i am not sure of that also.. :( Can anyone please confirm it ??
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 11720
Re: The amount of coal a train burns each mile is directly propo  [#permalink]

Show Tags

New post 15 Jul 2018, 00:42
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources
Signature Read More
GMAT Club Bot
Re: The amount of coal a train burns each mile is directly propo   [#permalink] 15 Jul 2018, 00:42
Print view
First unread post
Display posts from previous: Sort by

The amount of coal a train burns each mile is directly propo

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderators: chetan2u, VeritasKarishma, Bunuel, amanvermagmat, gmatbusters

Search for:





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions