GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 22 Jan 2019, 08:47

### 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

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

## Events & Promotions

###### Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### The winners of the GMAT game show

January 22, 2019

January 22, 2019

10:00 PM PST

11:00 PM PST

In case you didn’t notice, we recently held the 1st ever GMAT game show and it was awesome! See who won a full GMAT course, and register to the next one.
• ### Key Strategies to Master GMAT SC

January 26, 2019

January 26, 2019

07:00 AM PST

09:00 AM PST

Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.

# A certain quantity is measured on two different scales, the

Author Message
Manager
Joined: 10 Oct 2008
Posts: 56
A certain quantity is measured on two different scales, the  [#permalink]

### Show Tags

Updated on: 17 Dec 2013, 07:27
1
1
22
00:00

Difficulty:

55% (hard)

Question Stats:

64% (01:04) correct 36% (01:07) wrong based on 289 sessions

### HideShow timer Statistics

A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly. Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively. What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?

A. 20
B. 36
C. 48
D. 60
E. 84

OPEN DISCUSSION OF THIS QUESTION IS HERE: a-certain-quantity-is-measured-on-two-different-scales-the-r-147469.html

Originally posted by Jcpenny on 11 Nov 2008, 19:11.
Last edited by Bunuel on 17 Dec 2013, 07:27, edited 1 time in total.
Renamed the topic, edited the question, added the OA and moved to PS forum.
Director
Joined: 14 Aug 2007
Posts: 673

### Show Tags

11 Nov 2008, 19:56
15
13
Jcpenny wrote:
A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly. Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively. What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?

A. 20
B. 36
C. 48
D. 60
E. 84

Note that scales are related "linearly"

y = mx + c
30 = m*6 + c
60 = m*24 + c

solving m =5/3, c =20

100 = 5/3 * x + 20

80 * 3/5 = x therefore x =48

C.
SVP
Joined: 30 Apr 2008
Posts: 1820
Location: Oklahoma City
Schools: Hard Knocks

### Show Tags

11 Nov 2008, 20:44
6
2
Because these scales are related linearly, we need to figure out the "slope" which will then be able to tell us how much one scale changes with 1 unit of movement on the other one.

The R-scale moves 18 (from 6 to 24 is 24-6=18) for every 30 (30 to 60 is 60-30=30) that the S-Scale moves. This is a 18/30 slope, or 3/5 slope.

Lets check to see if this is indeed the right slope.

R=6, S=30
R=9, S=35
R=12, S=40
R=15, S=45
R=18, S=50
R=21, S=55
R=24, S=60 <---Just like it should

If we're going to 100 from 60, that's a difference of 40, and if we go in increments of 5, that's 40/5 increments, or 8 increments, so on the other scale that goes in increments of 3, it's 8 * 3=24 more units, or 48 on the R-Scale = 100 on the S-Scale. Answer C.

alpha_plus_gamma wrote:
Jcpenny wrote:
A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly. Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively. What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?

A. 20
B. 36
C. 48
D. 60
E. 84

Note that scales are related "linearly"

y = mx + c
30 = m*6 + c
60 = m*24 + c

solving m =5/3, c =20

100 = 5/3 * x + 20

80 * 3/5 = x therefore x =48

C.

_________________

------------------------------------
J Allen Morris
**I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a\$\$.

GMAT Club Premium Membership - big benefits and savings

SVP
Joined: 07 Nov 2007
Posts: 1662
Location: New York

### Show Tags

11 Nov 2008, 21:34
11
5
Jcpenny wrote:
A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly. Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively. What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?

A. 20
B. 36
C. 48
D. 60
E. 84

(60-30)/(24-6)= (100-60)/(x-24)

--> x-24 = 40*18/30 =24
-->x=48

C
_________________

Smiling wins more friends than frowning

Math Expert
Joined: 02 Sep 2009
Posts: 52386
Re: A certain quantity is measured on two different scales, the  [#permalink]

### Show Tags

17 Dec 2013, 07:28
7
10
A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly. Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively. What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?
A. 20
B. 36
C. 48
D. 60
E. 84

As R increases by 18 (from 6 to 24), S increases by 30 (from 30 to 60). Thus increase of 18 in R corresponds to increase of 30 in S.

Therefore change of 70 in S from 30 (when R is 6) to 100 must correspond to change of 70/30*18=42 in R. Hence, 100 in S corresponds to 6+42=48 in R.

OPEN DISCUSSION OF THIS QUESTION IS HERE: a-certain-quantity-is-measured-on-two-different-scales-the-r-147469.html
_________________
Non-Human User
Joined: 09 Sep 2013
Posts: 9464
Re: A certain quantity is measured on two different scales, the  [#permalink]

### Show Tags

29 Jul 2018, 11:44
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.
_________________
Re: A certain quantity is measured on two different scales, the &nbs [#permalink] 29 Jul 2018, 11:44
Display posts from previous: Sort by