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

It is currently 21 Apr 2019, 11:30

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

Bricklayer Brenda would take 9 hours to build a chimney alone, and bri

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

Hide Tags

 
Manager
Manager
avatar
G
Status: Manager
Joined: 02 Nov 2018
Posts: 179
Location: Bangladesh
GMAT ToolKit User CAT Tests
Bricklayer Brenda would take 9 hours to build a chimney alone, and bri  [#permalink]

Show Tags

New post 14 Mar 2019, 11:09
4
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

57% (03:02) correct 43% (03:06) wrong based on 21 sessions

HideShow timer Statistics

Bricklayer Brenda would take 9 hours to build a chimney alone, and bricklayer Brandon would take 10 hours to build it alone. When they work together, they talk a lot, and their combined output is decreased by 10 bricks per hour. Working together, they build the chimney in 5 hours. How many bricks are in the chimney?

(A) 500
(B) 900
(C) 950
(D) 1000
(E) 1900

_________________
Give a kudos if u find my post helpful. kudos motivates active discussions :)

Manager
Manager
avatar
G
Joined: 14 May 2018
Posts: 99
Location: India
Concentration: Finance, Entrepreneurship
GMAT 1: 710 Q49 V38
GPA: 4
Re: Bricklayer Brenda would take 9 hours to build a chimney alone, and bri  [#permalink]

Show Tags

New post 14 Mar 2019, 12:50
3
TyrionLannister wrote:
Bricklayer Brenda would take 9 hours to build a chimney alone, and bricklayer Brandon would take 10 hours to build it alone. When they work together, they talk a lot, and their combined output is decreased by 10 bricks per hour. Working together, they build the chimney in 5 hours. How many bricks are in the chimney?

(A) 500 (B) 900 (C) 950 (D) 1000 (E) 1900



Brenda is doing 11.11% of the work in one hour.
Brandon does 10% of the work in 1 hour.
So, working together they should do 21.11% of the work in 1 hour.
However, together they take 5 hours,i.e. 20% of work per hour.
i.e. output has decreased by 1.11% per hour
1.11%=10 bricks
==>100%=1000/1.11=900 bricks

Ans:B
_________________
Please hit kudos if you like my answers.

GMAT:710 (Q49,V38,IR8,AWA5)
Manager
Manager
avatar
B
Joined: 09 Nov 2015
Posts: 51
Re: Bricklayer Brenda would take 9 hours to build a chimney alone, and bri  [#permalink]

Show Tags

New post 26 Mar 2019, 00:30
1
Brenda can do 1/9th of the work in 1 hr and Brandon can do 1/10th of the work in 1 hr.
Working together they can do (1/9+1/10)=19/90th of the work in 1 hr which means that together they can complete the work in 90/19 hours.
Now let the total number of bricks in the chimney be 'x'.
So had they worked at their usual speed (without wasting time by gossiping) they would would have laid 'x/(90/19)'=19x/90 bricks in 1 hr. But they did gossip and ended up finishing the work in 5 hours which means that they laid x/5 bricks in an hour.
We are told that their combined output decreased by 10 bricks/hr due to the time they wasted.

Thus, 19x/90 - x/5 = 10. Solving we have x=900. Ans.: B
GMAT Club Bot
Re: Bricklayer Brenda would take 9 hours to build a chimney alone, and bri   [#permalink] 26 Mar 2019, 00:30
Display posts from previous: Sort by

Bricklayer Brenda would take 9 hours to build a chimney alone, and bri

  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®.