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 Rscale
corresponds to a measurement of 100 on the S-scale?
A. 20
B. 36
C. 48
D. 60
E. 84
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
GMAT Set 7 Q10
This topic has expert replies
-
GMATGuruNY
- GMAT Instructor
- Posts: 15539
- Joined: Tue May 25, 2010 12:04 pm
- Location: New York, NY
- Thanked: 13060 times
- Followed by:1906 members
- GMAT Score:790
Since the relationship between R and S is linear, any pair of points (R,S) must yield the same slope.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
Given points are (6,30), and (24,60).
Slope = (S₂ - S�)/(R₂ - R�) = (60-30)/(24-6) = 30/18 = 5/3.
(6,30) and (R,100) must yield the same slope.
(100-30)/(R-6) = 5/3.
70/(R-6) = 5/3.
Cross-mulitplying, we get:
5R-30 = 210.
R = 48.
The correct answer is C.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
GMAT/MBA Expert
-
[email protected]
- Elite Legendary Member
- Posts: 10392
- Joined: Sun Jun 23, 2013 6:38 pm
- Location: Palo Alto, CA
- Thanked: 2867 times
- Followed by:511 members
- GMAT Score:800
Hi Abhijit K,
The answer choices to this question are 'spread out' enough that you can use a bit of logic to estimate the correct answer.
We're told that the relationship between the values on the R-Scale and S-Scale are LINEAR, which means that as one value increases, the other value will increase by a fixed amount.
We're then told the relationship between the R-Scale and S-Scale for two sets of values (6 and 30; 24 and 60). Notice how that when the R-scale value increases from 6 to 24 (an increase of 18), the S-scale value increases from 30 to 60 (an increase of 30). The question asks for the relative R-scale value when the S-scale value is 100.
Since an increase of 30 the S-scale = an increase of 18 on the R-scale, when we go from 60 to 100 on the S-scale, we're increasing by 40 (a little more than 30)....so the increase on the R-scale should be a little more than 18....
24 + (a bit more than 18)..... = a bit more than 42....
There's only one answer that matches:
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
The answer choices to this question are 'spread out' enough that you can use a bit of logic to estimate the correct answer.
We're told that the relationship between the values on the R-Scale and S-Scale are LINEAR, which means that as one value increases, the other value will increase by a fixed amount.
We're then told the relationship between the R-Scale and S-Scale for two sets of values (6 and 30; 24 and 60). Notice how that when the R-scale value increases from 6 to 24 (an increase of 18), the S-scale value increases from 30 to 60 (an increase of 30). The question asks for the relative R-scale value when the S-scale value is 100.
Since an increase of 30 the S-scale = an increase of 18 on the R-scale, when we go from 60 to 100 on the S-scale, we're increasing by 40 (a little more than 30)....so the increase on the R-scale should be a little more than 18....
24 + (a bit more than 18)..... = a bit more than 42....
There's only one answer that matches:
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
