BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

OG 11 #99

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 80
Joined: Fri Apr 13, 2007 7:02 am
Location: Long Island

OG 11 #99

by maolivie » Sat May 12, 2007 9:21 am
How would you guys explain this reasoning?

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
D) 8^10-3^10

According to the solution, each increase of 1 in the scale creats an intensity increase of a factor of 10? How is that determined?
Top
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 986
Joined: Wed Dec 20, 2006 11:07 am
Location: India
Thanked: 51 times
Followed by:1 members

Re: OG 11 #99

by gabriel » Sat May 12, 2007 1:32 pm
maolivie wrote:How would you guys explain this reasoning?

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
D) 8^10-3^10

According to the solution, each increase of 1 in the scale creats an intensity increase of a factor of 10? How is that determined?

the darkened part answers ur question .. wen u move from n to n+1 the intensity increases by 10 times .. and n+1 is 1 greater than n on the scale .. post if any more doubts ...
Top
User avatar
Community Manager
Posts: 789
Joined: Sun Jan 28, 2007 3:51 pm
Location: Silicon valley, California
Thanked: 30 times
Followed by:1 members

Re: OG 11 #99

by jayhawk2001 » Sat May 12, 2007 6:59 pm
maolivie wrote:How would you guys explain this reasoning?

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
D) 8^10-3^10

According to the solution, each increase of 1 in the scale creats an intensity increase of a factor of 10? How is that determined?
Just elaborating on Gabriel's point, this is like the Richter scale (for Earthquakes).

A value of 2 is 10 times the value of 1. 3 is 10 times 2 which is
100 times 1. By induction,

Intensity at level n = 10^n * intensity-at-level-1

So, if you know the intensity at 3 say x

Intensity at 4 = 10 * intensity at 3
Intensity at 5 = 10^2 * intensity at 3
...
Intensity at 8 = 10^5 * intensity at 3
Top
Legendary Member
Posts: 559
Joined: Tue Mar 27, 2007 1:29 am
Thanked: 5 times
Followed by:2 members

by Cybermusings » Sat May 12, 2007 11:39 pm
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
D) 8^10-3^10

Reading n --- intensity x (assume)
Reading n+1 ---- intensity 10x
Reading n+2 ---- intensity 10(10x) = 100x
Reading 3 ---- intensity x
Reading 4 i.e. n+1 ---- intensity 10x
Reading 8 --- intensity 10^5
Top
Senior | Next Rank: 100 Posts
Posts: 80
Joined: Fri Apr 13, 2007 7:02 am
Location: Long Island

by maolivie » Sun May 13, 2007 5:11 pm
Hey, thanks for your replies.

So...

does a reading of 8 (mean 7+1), equate to 10^8, and then a reading of 3 (2+1) equate to 10^3? Then it becomes the difference between the two, so you subtract?
Top
User avatar
Community Manager
Posts: 789
Joined: Sun Jan 28, 2007 3:51 pm
Location: Silicon valley, California
Thanked: 30 times
Followed by:1 members

by jayhawk2001 » Sun May 13, 2007 5:42 pm
maolivie wrote:Hey, thanks for your replies.

So...

does a reading of 8 (mean 7+1), equate to 10^8, and then a reading of 3 (2+1) equate to 10^3? Then it becomes the difference between the two, so you subtract?
You shouldn't subtract as you are asked to find the "number of times"
one is greater than the other.
Top
Post new topic Post Reply
• Page 1 of 1