• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

• Free Practice Test & Review
How would you score if you took the GMAT

Available with Beat the GMAT members only code

• Get 300+ Practice Questions

Available with Beat the GMAT members only code

• Award-winning private GMAT tutoring
Register now and save up to $200 Available with Beat the GMAT members only code • Free Veritas GMAT Class Experience Lesson 1 Live Free Available with Beat the GMAT members only code • 5 Day FREE Trial Study Smarter, Not Harder Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • Reach higher with Artificial Intelligence. Guaranteed Now free for 30 days Available with Beat the GMAT members only code • 5-Day Free Trial 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • Free Trial & Practice Exam BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code ## operations on rational numbers tagged by: Brent@GMATPrepNow This topic has 4 expert replies and 0 member replies marat_isr Newbie | Next Rank: 10 Posts Joined 06 Mar 2014 Posted: 3 messages #### operations on rational numbers Fri Mar 03, 2017 8:37 am On a scale that measures the intensity of a certain phenomenon, a reading of n+1 corresponds to an intensity that is 10 times the intensity corresponding to a reading of n. On that scale, the intensity corresponding to a reading of 8 is how many times as great as the intensity corresponding to a reading of 3? a)5 b)50 c)10^5 D)5^10 e)8^10-3^10 ### GMAT/MBA Expert Jay@ManhattanReview GMAT Instructor Joined 22 Aug 2016 Posted: 1026 messages Followed by: 22 members Upvotes: 470 Sat Mar 04, 2017 1:32 am marat_isr wrote: On a scale that measures the intensity of a certain phenomenon, a reading of n+1 corresponds to an intensity that is 10 times the intensity corresponding to a reading of n. On that scale, the intensity corresponding to a reading of 8 is how many times as great as the intensity corresponding to a reading of 3? a)5 b)50 c)10^5 D)5^10 e)8^10-3^10 Hi marat_isr, The meaning of the phrase, "a reading of n+1 corresponds to an intensity that is 10 times the intensity corresponding to a reading of n" is simply that the next reading is 10 times the previous reading. And this is true for all the readings on the given scale. Say the reading for 1 = 1; Thus, the reading for 2 = 1*10 = 10; Similarly, the reading for 3 = 10*10 = 10^2 Similarly, the reading for 4 = 10*10 = 10^4 . . . Similarly, the reading for 8 = 10*10 = 10^7 => Reading for 8 / Reading for 3 = 10^7 / 10^2 = 10^5. The correct answer: C Hope this helps! Relevant book: Manhattan Review GMAT Word Problems Guide -Jay _________________ Manhattan Review GMAT Prep Locations: New York | Barcelona | Manila | Melbourne | and many more... Schedule your free consultation with an experienced GMAT Prep Advisor! Click here. ### GMAT/MBA Expert Rich.C@EMPOWERgmat.com Elite Legendary Member Joined 23 Jun 2013 Posted: 9316 messages Followed by: 478 members Upvotes: 2867 GMAT Score: 800 Fri Mar 03, 2017 9:55 am Hi marat_isr, GMAT questions are often written in such a way that you can approach the question in a number of different ways and still get the correct answer. The level of 'complexity' with which you choose to approach each prompt is up to you, but you'd be surprised how often there's a 'simple' way to deal with a prompt. The key to this question is understanding the different between "N" and "N+1" We're told that these two values are "intensities" and that "N+1" is "10 times more intense" than "N"; this essentially means that IF you add 1 to any "intensity", then the intensity gets 10 times bigger. So, let's say N = 3 has an intensity of 1â€¦. N = 3 ---> intensity of 1 N = 4 ---> intensity of 10 (10 times the intensity of N = 3) N = 5 ---> intensity of 100 (10 times the intensity of N = 4) N = 6 ---> intensity of 1,000 (10 times the intensity of N = 5) N = 7 ---> intensity of 10,000 (10 times the intensity of N = 6) etc. Thinking in those terms, it's not difficult to get to the correct answer. GMAT assassins aren't born, they're made, Rich _________________ Contact Rich at Rich.C@empowergmat.com ### GMAT/MBA Expert DavidG@VeritasPrep Legendary Member Joined 14 Jan 2015 Posted: 2667 messages Followed by: 120 members Upvotes: 1153 GMAT Score: 770 Fri Mar 03, 2017 8:44 am marat_isr wrote: On a scale that measures the intensity of a certain phenomenon, a reading of n+1 corresponds to an intensity that is 10 times the intensity corresponding to a reading of n. On that scale, the intensity corresponding to a reading of 8 is how many times as great as the intensity corresponding to a reading of 3? a)5 b)50 c)10^5 D)5^10 e)8^10-3^10 Let's call the intensity at a reading of 3: x. Reading of 4: 10x Reading of 5: (10^2) * x Reading of 6: (10^3) * x Reading of 7: (10^4) * x Reading of 8: (10^5) * x Thus a reading of 8, or 10^5 * x, would be 10^5 times a reading of 3, or x. The answer is C _________________ Veritas Prep | GMAT Instructor Veritas Prep Reviews Save$100 off any live Veritas Prep GMAT Course

Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now!

### GMAT/MBA Expert

Brent@GMATPrepNow GMAT Instructor
Joined
08 Dec 2008
Posted:
11414 messages
Followed by:
1229 members
5254
GMAT Score:
770
Fri Mar 03, 2017 8:45 am
Quote:
On a scale that measures the intensity of a certain phenomenon, a reading of n+1 corresponds to an intensity that is 10 times the intensity corresponding to a reading of n. On that scale, the intensity corresponding to a reading of 8 is how many times as great as the intensity corresponding to a reading of 3?

A) 5
B) 50
C) 10^5
D) 5^10
E) 8^10 - 3^10
If we start with a NICE NUMBER, it won't take us long to list the intensity for each reading, starting at a reading of 3 and stopping at a reading of 8.

Say a reading of 3 means an intensity of 1
So, a reading of 4 means an intensity of 10
A reading of 5 means an intensity of 100
A reading of 6 means an intensity of 1,000
A reading of 7 means an intensity of 10,000
A reading of 8 has an intensity of 100,000

100,000 is 100,000 times bigger than 1.
Since 100,000 = 10^5, the correct answer is C

Cheers,
Brent

_________________
Brent Hanneson â€“ Founder of GMATPrepNow.com
Use our video course along with

Check out the online reviews of our course
Come see all of our free resources

GMAT Prep Now's comprehensive video course can be used in conjunction with Beat The GMATâ€™s FREE 60-Day Study Guide and reach your target score in 2 months!

### Best Conversation Starters

1 lheiannie07 80 topics
2 LUANDATO 62 topics
3 ardz24 52 topics
4 AAPL 47 topics
5 Roland2rule 43 topics
See More Top Beat The GMAT Members...

### Most Active Experts

1 Jeff@TargetTestPrep

Target Test Prep

134 posts
2 Brent@GMATPrepNow

GMAT Prep Now Teacher

131 posts
3 GMATGuruNY

The Princeton Review Teacher

130 posts
4 Rich.C@EMPOWERgma...

EMPOWERgmat

128 posts
5 Scott@TargetTestPrep

Target Test Prep

110 posts
See More Top Beat The GMAT Experts