Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 17 Jul 2019, 03:39

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

If the numerator of a fraction is decreased 25 percent and the denomi

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56268
If the numerator of a fraction is decreased 25 percent and the denomi  [#permalink]

Show Tags

New post 18 Feb 2018, 23:10
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

76% (01:40) correct 24% (01:57) wrong based on 57 sessions

HideShow timer Statistics


Senior PS Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 3360
Location: India
GPA: 3.12
If the numerator of a fraction is decreased 25 percent and the denomi  [#permalink]

Show Tags

New post 18 Feb 2018, 23:14
Bunuel wrote:
If the numerator of a fraction is decreased 25 percent and the denominator of that fraction is increased 25 percent, then the difference between the resulting and the original fractions represents what percentage decrease?

(A) 40%

(B) 45%

(C) 50%

(D) 60%

(E) 75%


Let the original fraction will be \(\frac{x}{y}\)

If the numerator is decreased 25% and the denominator is increased 25%,
the resultant fraction becomes \(\frac{0.75x}{1.25y} = \frac{3}{5}*\frac{x}{y}\)(60% of its original value)

Therefore, the percentage decrease should be 40%(Option A)
_________________
You've got what it takes, but it will take everything you've got
Senior SC Moderator
avatar
V
Joined: 22 May 2016
Posts: 3064
If the numerator of a fraction is decreased 25 percent and the denomi  [#permalink]

Show Tags

New post 20 Feb 2018, 01:34
Bunuel wrote:
If the numerator of a fraction is decreased 25 percent and the denominator of that fraction is increased 25 percent, then the difference between the resulting and the original fractions represents what percentage decrease?

(A) 40%

(B) 45%

(C) 50%

(D) 60%

(E) 75%

Assigning numbers here works well.

Original fraction
Use numbers that yield easy results when multiplied by \(\frac{3}{4}\) (.75) and \(\frac{5}{4}\) (1.25)

Let the original fraction = \(\frac{100}{100}\) (which = 1)

New fraction
The numerator is decreased 25 percent. The denominator increases by 25 percent. New fraction:

\(\frac{75}{125}\) (which =\(\frac{3}{5}\))

Percent decrease?
Percent decrease generally:

\(\frac{|New-Old|}{Old}*100\)

Percent decrease here \(\frac{|\frac{3}{5}-1|}{1}*100)=(|-\frac{2}{5}|*100)=(0.4*100)=\)
40 percent decrease

Answer A
_________________
SC Butler has resumed!
Get two SC questions to practice, whose links you can find by date, here.


Tell me, what is it you plan to do with your one wild and precious life? -- Mary Oliver
Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2823
Re: If the numerator of a fraction is decreased 25 percent and the denomi  [#permalink]

Show Tags

New post 22 Feb 2018, 09:17
Bunuel wrote:
If the numerator of a fraction is decreased 25 percent and the denominator of that fraction is increased 25 percent, then the difference between the resulting and the original fractions represents what percentage decrease?

(A) 40%

(B) 45%

(C) 50%

(D) 60%

(E) 75%


We can let the original fraction = n/d and the new fraction = 0.75n/1.25d = (3n/4)/(5d/4) = 12n/20d = 3n/5d

Now we can determine the percent decrease:

[(3n/5d) - (5n/5d)]/(n/d) x 100

-2n/5d x d/n x 100 = -2/5 x 100 = -40, a 40% decrease

Alternate Solution:

Let’s let the original fraction be 1/1. When the numerator is decreased by 25% and the denominator is increased by 25%, the new fraction is 0.75/1.25 = 75/125 = 3/5.

We use the percent change formula (new - old)/old x 100%:

(3/5 -1)/1 x 100% = -2/5 x 100% = -40 percent, which is a 40% decrease.

Answer: A
_________________

Jeffrey Miller

Head of GMAT Instruction

Jeff@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

GMAT Club Bot
Re: If the numerator of a fraction is decreased 25 percent and the denomi   [#permalink] 22 Feb 2018, 09:17
Display posts from previous: Sort by

If the numerator of a fraction is decreased 25 percent and the denomi

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne