NEW HERE? LEARN MORE
closeclose
Last visit was: 24 Apr 2024, 16:24 It is currently 24 Apr 2024, 16:24
Decision Tracker
My Rewards
New posts
New comers' posts

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

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

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
avatar
gmatmathguy123
Intern
Intern
Joined: 04 May 2010
Posts: 1
Own Kudos [?]: 27 [27]
Given Kudos: 0
Send PM
The amount of coal a train burns each mile is directly propo [#permalink] New post   Updated on: 26 May 2014, 02:11
1
Kudos
26
Bookmarks
00:00
A
B
C
D
E

Difficulty:

15% (low)

Question Stats:

77% (01:22) correct 23% (01:22) wrong based on 740 sessions
Hide Show 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.


Show 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...)
ShowHide Answer
Official Answer
C

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
User avatar
nverma
Manager
Manager
Joined: 24 Jul 2009
Posts: 155
Own Kudos [?]: 488 [2]
Given Kudos: 0
Send PM
Re: DS question... [#permalink] New post   04 May 2010, 07:29
2
Kudos
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.
User avatar
dixitraghav
Manager
Manager
Joined: 16 Feb 2010
Posts: 77
Own Kudos [?]: 128 [0]
Given Kudos: 17
Send PM
Re: DS question... [#permalink] 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.
avatar
subratam99
Intern
Intern
Joined: 21 Mar 2010
Posts: 8
Own Kudos [?]: 4 [0]
Given Kudos: 0
Send PM
GMAT ToolKit User
Re: DS question... [#permalink] 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
avatar
Sindbad
Intern
Intern
Joined: 11 Aug 2013
Posts: 21
Own Kudos [?]: 19 [0]
Given Kudos: 22
Location: India
Concentration: Finance, General Management
GMAT 1: 620 Q47 V28
GPA: 3.23
WE:Information Technology (Investment Banking)
Send PM
Re: The amount of coal a train burns each mile is directly propo [#permalink] 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
avatar
ashutosh4018
Intern
Intern
Joined: 05 Jun 2016
Posts: 1
Own Kudos [?]: [0]
Given Kudos: 1
Send PM
Re: The amount of coal a train burns each mile is directly propo [#permalink] 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 ??
User avatar
G
Basshead
Director
Director
Joined: 09 Jan 2020
Posts: 966
Own Kudos [?]: 223 [0]
Given Kudos: 434
Location: United States
Send PM
Re: The amount of coal a train burns each mile is directly propo [#permalink] New post   13 Oct 2020, 10:52
No calculation is needed for this question. We are told the amount of coal a train burns each mile is directly proportional to the speed at which it travels. So we will need to know the speed of the train.

(1) Tells us the amount of coal burned for a given speed. However, we do not know the speed of the train for this particular trip. Insufficient.
(2) Gives us the speed of the train. However, we do not know the proportion of coal/per mile burned. Insufficient.

(1 & 2) We have the proportionality constant and the speed of the train. Sufficient.
User avatar
B
Jitesh8
Intern
Intern
Joined: 11 Nov 2022
Posts: 29
Own Kudos [?]: 7 [0]
Given Kudos: 4
Location: India
Send PM
Re: The amount of coal a train burns each mile is directly propo [#permalink] New post   23 Mar 2023, 06:44
ashutosh4018 wrote:
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 ??








This is nice point to note

Thank you for highlighting this point.
GMAT Club Bot
gmatclubot
Re: The amount of coal a train burns each mile is directly propo [#permalink]
23 Mar 2023, 06:44
Moderator:
Bunuel
Math Expert
92900 posts

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