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

It is currently 21 Feb 2019, 14:07

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
Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
  • Online GMAT boot camp for FREE

     February 21, 2019

     February 21, 2019

     10:00 PM PST

     11:00 PM PST

    Kick off your 2019 GMAT prep with a free 7-day boot camp that includes free online lessons, webinars, and a full GMAT course access. Limited for the first 99 registrants! Feb. 21st until the 27th.
  • Free GMAT RC Webinar

     February 23, 2019

     February 23, 2019

     07:00 AM PST

     09:00 AM PST

    Learn reading strategies that can help even non-voracious reader to master GMAT RC. Saturday, February 23rd at 7 AM PT

If 45 people built 1/2 of a pyramid in 288 days, how many days did it

  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: 53063
If 45 people built 1/2 of a pyramid in 288 days, how many days did it  [#permalink]

Show Tags

New post 09 Oct 2018, 00:11
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

73% (02:43) correct 27% (03:23) wrong based on 94 sessions

HideShow timer Statistics

If 45 people built \(\frac{1}{2}\) of a pyramid in 288 days, how many days did it take 65 people to build the next \(\frac{1}{6}\) the pyramid, rounded to the nearest integer, assuming each person works at the same constant rate?


(A) 66 days

(B) 77 days

(C) 88 days

(D) 87 days

(E) 76 days

_________________

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

Intern
Intern
avatar
B
Joined: 15 Dec 2012
Posts: 19
CAT Tests
Re: If 45 people built 1/2 of a pyramid in 288 days, how many days did it  [#permalink]

Show Tags

New post 09 Oct 2018, 03:38
45 people complete the job in 288x2 days
total man days= 288x2x45
65 man will complete the job in 288x2x45/65 days
65 man will comlete 1/6th of the job in 288x2x45/(65x6)= 66 days
Board of Directors
User avatar
P
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4391
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member CAT Tests
Re: If 45 people built 1/2 of a pyramid in 288 days, how many days did it  [#permalink]

Show Tags

New post 09 Oct 2018, 07:30
Bunuel wrote:
If 45 people built \(\frac{1}{2}\) of a pyramid in 288 days, how many days did it take 65 people to build the next \(\frac{1}{6}\) the pyramid, rounded to the nearest integer, assuming each person works at the same constant rate?

(A) 66 days

(B) 77 days

(C) 88 days

(D) 87 days

(E) 76 days


\(\frac{M_1 D_1}{W_1} = \frac{M_2 D_2}{W_2}\)

Or, \(\frac{45*288}{1/2} = \frac{65* D_2}{1/6}\)

Or, \(45*288*2 = 65*2*D_2\)

So, \(D_2 ~ 66\), Answer must be (A) 66
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Target Test Prep Representative
User avatar
P
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 4944
Location: United States (CA)
Re: If 45 people built 1/2 of a pyramid in 288 days, how many days did it  [#permalink]

Show Tags

New post 12 Oct 2018, 06:55
Bunuel wrote:
If 45 people built \(\frac{1}{2}\) of a pyramid in 288 days, how many days did it take 65 people to build the next \(\frac{1}{6}\) the pyramid, rounded to the nearest integer, assuming each person works at the same constant rate?


(A) 66 days

(B) 77 days

(C) 88 days

(D) 87 days

(E) 76 days


The rate of 45 people is (1/2)/288 = 1/576, which means that 45 people can build 1/576 of a pyramid in one day.

We can use a proportion to determine the rate x of 65 people:

45/(1/576) = 65/x

45 * 576 * x = 65

9 * 576 * x = 13

x = 13/5184. This value 13/5184 means that 65 people can build 13/5184 of a pyramid in one day.

So, to build 1/6 of a pyramid, it will take 65 people (1/6)/(13/5184) = 5184/78 ≈ 66 days.

Answer: A
_________________

Scott Woodbury-Stewart
Founder and CEO

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

GMAT Club Bot
Re: If 45 people built 1/2 of a pyramid in 288 days, how many days did it   [#permalink] 12 Oct 2018, 06:55
Display posts from previous: Sort by

If 45 people built 1/2 of a pyramid in 288 days, how many days did it

  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®.