I know it supposed to be an easy one, but i dont understand how OG11 explains it.
from pg 97 ex. 39
answer: For all large values of x, the value of x/(2x+1) is going to be very close to the value of x/2x, which is equal to 1/2.
could you help?
If x>3,000, then x/(2x+1) is closest to...
This topic has expert replies
-
- Senior | Next Rank: 100 Posts
- Posts: 51
- Joined: Wed Oct 08, 2008 12:50 pm
-
- Senior | Next Rank: 100 Posts
- Posts: 51
- Joined: Wed Oct 08, 2008 12:50 pm
GMAT/MBA Expert
- Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7249
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
Let's say x = 3001; we have:GMATCHPOINT wrote:
If x > 3000, then the value of (x)/(2x+1) is closest to?
A. 1/6
B. 1/3
C. 10/21
D. 1/2
E. 3/2
3001/(6002 + 1), which is about 3,000/6,000 = 1/2.
Answer: D
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews
-
- GMAT Instructor
- Posts: 2630
- Joined: Wed Sep 12, 2012 3:32 pm
- Location: East Bay all the way
- Thanked: 625 times
- Followed by:119 members
- GMAT Score:780
It is the night of the zombie threads tonight!
Just pick a number. Say x = 5000. Then x/(2x + 1) = 5000/10001, which is really close to 5000/10000, or 1/2.
Just pick a number. Say x = 5000. Then x/(2x + 1) = 5000/10001, which is really close to 5000/10000, or 1/2.
- thucanh711
- Newbie | Next Rank: 10 Posts
- Posts: 3
- Joined: Sat Dec 23, 2017 2:48 am
Hi there, I think it is a little bit too late to answer your post, but just do it anyway, shall we?
The problem is related to the limit of a function, just in case you want to have a deeper understand.
When the variable x is as great as 3000, adding 1 or not to 2x does not affect its value. In another word, plus one is a subtle change to the variable 2x. Therefore, you can treat 2x + 1 as 2x alone.
As a result: x/2x is merely the same as x/2x+1
This is true only if variable x has a great value, or has an infinite limit.
If x is just about 5, for example, adding 1 to 2x might cause a proper change.
x/2x = 0.5
x/2x+1 = 0.45
Hope that was helpful for you.
The problem is related to the limit of a function, just in case you want to have a deeper understand.
When the variable x is as great as 3000, adding 1 or not to 2x does not affect its value. In another word, plus one is a subtle change to the variable 2x. Therefore, you can treat 2x + 1 as 2x alone.
As a result: x/2x is merely the same as x/2x+1
This is true only if variable x has a great value, or has an infinite limit.
If x is just about 5, for example, adding 1 to 2x might cause a proper change.
x/2x = 0.5
x/2x+1 = 0.45
Hope that was helpful for you.