|
Author |
Message |
|
TAGS:
|
|
|
Manager
Joined: 10 Feb 2011
Posts: 121
Followers: 1
Kudos [?]:
6
[0], given: 10
|
4. (GC) If 25/(x/5) = (1/25)/125 then x = ? (A) 5-2 (B) 52 [#permalink]
 15 Mar 2011, 16:40
Question Stats:
50% (01:41) correct
50% (00:56) wrong based on 0 sessions
4. (GC) If 25/(x/5) = (1/25)/125 then x = ? (A) 5^-2 (B) 5^2 (C) 5^3 (D) 5^8 (E) 5^11
Last edited by banksy on 16 Mar 2011, 09:00, edited 1 time in total.
|
|
|
|
|
|
|
Intern
Joined: 06 Feb 2011
Posts: 10
Followers: 0
Kudos [?]:
3
[0], given: 3
|
Re: 4. (GC) If 25/(x/5) = (1/25)/125 then x = ? (A) 5-2 (B) 52 [#permalink]
15 Mar 2011, 18:37
rewrite as:
25*(5/x) = (1/25)*(1/125)
(5^3)/x = (1/(5^2))*(1/(5^3))
1/x = (1/(5^2))*(1/(5^3))*(1/(5^3))
1/x = 1/(5^7)
x = (5^7)
Where did you get that answer?
|
|
|
|
|
|
SVP
Joined: 16 Nov 2010
Posts: 1717
Location: United States (IN)
Concentration: Strategy, Technology
Followers: 26
Kudos [?]:
227
[0], given: 34
|
Re: 4. (GC) If 25/(x/5) = (1/25)/125 then x = ? (A) 5-2 (B) 52 [#permalink]
15 Mar 2011, 21:49
=> 125/x = 1/25 * 1/125 => x = 5^3 * 5^2 * 5^3 => x = 5^8 Perhaps the answer is D. I think the answer choices should read 5^-2, 5^2, 5^3, 5^8, 5^11. @banksy, could you please confirm the answer choices ?
_________________
Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)
Find out what's new at GMAT Club - latest features and updates
|
|
|
|
|
|
Intern
Joined: 06 Feb 2011
Posts: 10
Followers: 0
Kudos [?]:
3
[0], given: 3
|
Re: 4. (GC) If 25/(x/5) = (1/25)/125 then x = ? (A) 5-2 (B) 52 [#permalink]
16 Mar 2011, 05:11
Oops, I agree with the (5^8), bad adding skills.
|
|
|
|
|
|
Manager
Joined: 03 Jun 2010
Posts: 140
Location: Dubai, UAE
Schools: IE Business School, Manchester Business School, HEC Paris, Rotterdam School of Management, Babson College
Followers: 2
Kudos [?]:
4
[0], given: 4
|
Re: 4. (GC) If 25/(x/5) = (1/25)/125 then x = ? (A) 5-2 (B) 52 [#permalink]
16 Mar 2011, 05:21
Why isnt it
25/(x/5)=(1/25)/125
25*5/x=1/25*1/125
125/x=1/(125)(25)
1/x=1/25
x=25
x=5^2
|
|
|
|
|
|
Math Forum Moderator
Joined: 20 Dec 2010
Posts: 2100
Followers: 108
Kudos [?]:
653
[0], given: 376
|
Re: 4. (GC) If 25/(x/5) = (1/25)/125 then x = ? (A) 5-2 (B) 52 [#permalink]
16 Mar 2011, 05:36
scbguy wrote: Why isnt it
25/(x/5)=(1/25)/125
25*5/x=1/25*1/125
125/x=1/(125)(25)
1/x=1/25
x=25
x=5^2 \frac{125}{x} = \frac{1}{125*25}If we cross multiply; x = 125*125*25x = 5^3*5^3*5^2x = 5^{(3+3+2)} = 5^8
_________________
~fluke
Find out what's new at GMAT Club - latest features and updates
|
|
|
|
|
|
Manager
Joined: 03 Jun 2010
Posts: 140
Location: Dubai, UAE
Schools: IE Business School, Manchester Business School, HEC Paris, Rotterdam School of Management, Babson College
Followers: 2
Kudos [?]:
4
[0], given: 4
|
Re: 4. (GC) If 25/(x/5) = (1/25)/125 then x = ? (A) 5-2 (B) 52 [#permalink]
16 Mar 2011, 05:59
got it thanks  , i thought we could cancel out 125
|
|
|
|
|
|
|
Re: 4. (GC) If 25/(x/5) = (1/25)/125 then x = ? (A) 5-2 (B) 52
[#permalink]
16 Mar 2011, 05:59
|
|
|
|
|
|
|
|
|
|
|
close
