GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 23 Oct 2018, 13:29

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

Over the course of a year, a certain microbrewery increased its beer

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50058
Over the course of a year, a certain microbrewery increased its beer  [#permalink]

Show Tags

New post 02 Dec 2014, 09:10
1
4
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

69% (01:53) correct 31% (01:47) wrong based on 149 sessions

HideShow timer Statistics

Tough and Tricky questions: Percents.



Over the course of a year, a certain microbrewery increased its beer output by 70 percent. At the same time, it decreased its total working hours by 20 percent. By what percent did this factory increase its output per hour?

A) 50%
B) 90%
C) 112.5%
D) 210%
E) 212.5%

Kudos for a correct solution.

Source: Chili Hot GMAT

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Most Helpful Community Reply
Manager
Manager
avatar
Joined: 12 Sep 2014
Posts: 151
Concentration: Strategy, Leadership
GMAT 1: 740 Q49 V41
GPA: 3.94
Re: Over the course of a year, a certain microbrewery increased its beer  [#permalink]

Show Tags

New post 02 Dec 2014, 10:27
3
2
Beware of this question's wording...

Let's take the original output to be 100 and the new output to be 170% or 170.
Let's take the original work hours to be 100 hours and the new work hours to be 80% or 80 hours.

The old output per work hour = 100/100 hours or 1.
The new output per work hour = 170/80 or 2.125. So the resulting increase is actually new minus old or 1.125 or 112.5%. Choice C
General Discussion
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1829
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: Over the course of a year, a certain microbrewery increased its beer  [#permalink]

Show Tags

New post 02 Dec 2014, 19:44
1
Answer = C) 112.5%

Time ........................... Rate .................. Work Done

100 ............................. 1 ............................. 100 (Assumption/ Original Values)

80 ......................... \(\frac{170}{80}\) ........................ 170 (Output increase by 70%)
(Time decrease by 20%)

Per cent increase in rate \(= (\frac{17}{8} - 1) * 100 = \frac{9}{8} * 100 = 112.5%\)
_________________

Kindly press "+1 Kudos" to appreciate :)

Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2830
Re: Over the course of a year, a certain microbrewery increased its beer  [#permalink]

Show Tags

New post 27 Nov 2017, 19:07
Bunuel wrote:

Over the course of a year, a certain microbrewery increased its beer output by 70 percent. At the same time, it decreased its total working hours by 20 percent. By what percent did this factory increase its output per hour?

A) 50%
B) 90%
C) 112.5%
D) 210%
E) 212.5%


We can let the old output per hour = m, the working hours = w, and n = the percentage increase in output per hour. Thus:

1.7mw = (0.8w)(m)(100 + n/100)

17/10 = (4/5)(100 + n)/100

170 = (4/5)(100 + n)

850 = 400 + 4n

450 = 4n

112.5 = n

Alternate Solution:

Let’s assume that the original output was 100 bottles in 50 hours. This would yield an output of 100 bottles/50 hours = 2 bottles/hour.
.
At the end of the year, the number of bottles was increased by 70%, which is 70 bottles, so the new output is 170 bottles. The total time was decreased by 20%, so the new time is 40 hours. Thus, the new output is 170 bottles/40 hours = 4.25 bottles/hour.

Using the formula percent increase = (new – old)/old x 100%, we have:

(4.25 – 2)/2 x 100% = 2.25/2 x 100% = 112.5%

Answer: C
_________________

Jeffery Miller
Head of GMAT Instruction

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Senior SC Moderator
avatar
V
Joined: 22 May 2016
Posts: 2040
Premium Member CAT Tests
Over the course of a year, a certain microbrewery increased its beer  [#permalink]

Show Tags

New post 30 Nov 2017, 10:54
Bunuel wrote:

Tough and Tricky questions: Percents.



Over the course of a year, a certain microbrewery increased its beer output by 70 percent. At the same time, it decreased its total working hours by 20 percent. By what percent did this factory increase its output per hour?

A) 50%
B) 90%
C) 112.5%
D) 210%
E) 212.5%

Kudos for a correct solution.

Source: Chili Hot GMAT

Above poster is right; wording can be tricky. I finally just wrote out the equation.

Output per hour =\(\frac{TotalOutput}{TotalHours}\)

Let original total output = 100
Let original total hours = 10
Original output per hour: \(\frac{100}{10}=
10\)

Total output increases by 70%; new output = 170
Total hours decrease by 20 percent; new hrs = 8
New output per hour: \(\frac{170}{8} = 21.25\)

Percent increase:
\(\frac{Old-New}{Old} * 100 =\)

\(\frac{(21.25-10)}{10} * 100 =\)

\((\frac{11.25}{10}=1.125 * 100= 112.5\) percent

Answer C
_________________

___________________________________________________________________
For what are we born if not to aid one another?
-- Ernest Hemingway

e-GMAT Representative
User avatar
P
Joined: 04 Jan 2015
Posts: 2069
Re: Over the course of a year, a certain microbrewery increased its beer  [#permalink]

Show Tags

New post 30 Nov 2017, 12:39
1
Bunuel wrote:

Tough and Tricky questions: Percents.



Over the course of a year, a certain microbrewery increased its beer output by 70 percent. At the same time, it decreased its total working hours by 20 percent. By what percent did this factory increase its output per hour?

A) 50%
B) 90%
C) 112.5%
D) 210%
E) 212.5%

Kudos for a correct solution.

Source: Chili Hot GMAT




Initial output per hour \(= \frac{N}{H}\)

New Output = N + 70% of N = 1.7N

New Time = H - 20% of H = 0.8H

New output per hour \(= \frac{1.7N}{0.8H} = \frac{17N}{8H}\)

Percent increase in output per hour \(=(\frac{17}{8} - 1) * 100 = \frac{9}{8} * 100 = 9 * 12.5 = 112.5%\)

Correct answer is Option C.
_________________








Register for free sessions
Number Properties | Algebra |Quant Workshop

Success Stories
Guillermo's Success Story | Carrie's Success Story

Ace GMAT quant
Articles and Question to reach Q51 | Question of the week

Must Read Articles
Number Properties – Even Odd | LCM GCD | Statistics-1 | Statistics-2
Word Problems – Percentage 1 | Percentage 2 | Time and Work 1 | Time and Work 2 | Time, Speed and Distance 1 | Time, Speed and Distance 2
Advanced Topics- Permutation and Combination 1 | Permutation and Combination 2 | Permutation and Combination 3 | Probability
Geometry- Triangles 1 | Triangles 2 | Triangles 3 | Common Mistakes in Geometry
Algebra- Wavy line | Inequalities

Practice Questions
Number Properties 1 | Number Properties 2 | Algebra 1 | Geometry | Prime Numbers | Absolute value equations | Sets



| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

GMAT Club Bot
Re: Over the course of a year, a certain microbrewery increased its beer &nbs [#permalink] 30 Nov 2017, 12:39
Display posts from previous: Sort by

Over the course of a year, a certain microbrewery increased its beer

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.