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

It is currently 19 Jun 2019, 00:19

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

Last Thursday, John assembled chairs at a rate of 3 chairs

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

Hide Tags

 
VP
VP
avatar
Joined: 22 Nov 2007
Posts: 1008
Last Thursday, John assembled chairs at a rate of 3 chairs  [#permalink]

Show Tags

New post Updated on: 05 Jan 2015, 03:42
1
18
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

74% (02:17) correct 26% (02:25) wrong based on 430 sessions

HideShow timer Statistics

Last Thursday, John assembled chairs at a rate of 3 chairs per hour for part of the day and Larry assembled no chairs. Last Friday, Larry assembled chairs at a rate of 4 chairs per hour for part of the day and John assembled no chairs. If John and Larry assembled chairs for a total of 7 hours during these two days, how many chairs did John assemble last Thursday?

(1) During these two days, John and Larry assembled a total of 25 chairs.
(2) During these two days, Larry assembled more chairs than John did.

Originally posted by marcodonzelli on 11 Mar 2008, 10:14.
Last edited by Bunuel on 05 Jan 2015, 03:42, edited 1 time in total.
Renamed the topic, edited the question, added the OA and moved to DS forum.
Director
Director
avatar
Joined: 10 Sep 2007
Posts: 833
Re: Last Thursday, John assembled chairs at a rate of 3 chairs  [#permalink]

Show Tags

New post 11 Mar 2008, 11:40
3
Suppose John worked J hours and Larry for L hours.
So from question we know that J + L = 7

Statement 1:
Tells that total chairs they collected is 25,
So we can write that 3J + 4L = 25
Now we have two equation and two unknowns so can be easily solved.

Statement 2:
Says Larry assembled more chairs than John. But does not tells how many chair in total they assembelled. So this alone is insufficient.

Answer A.
EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 14351
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: Last Thursday, John assembled chairs at a rate of 3 chairs  [#permalink]

Show Tags

New post 03 Jan 2015, 11:50
Hi All,

Since the numbers involved in this DS question are relatively small, we can "brute force" all of the possible options rather easily (if needed) to prove the correct answer.

We're given the rates of two people:
John assembles 3 chairs/hour
Larry assembles 4 chairs/hour
We're told that 7 hours of total work time was done, but that the two men did not work at the same time.

We're asked how many chairs JOHN assembled.

Assuming that we're not dealing with "fractional chairs", the number of possibilities is really limited - each man worked from 1 to 6 hours, so the possible outcomes are:

John/Larry/Total
3/24/27
6/20/26
9/16/25
12/12/24
15/8/23
18/4/22

Fact 1: A Total of 25 chairs were made.

There's just one option that fits this: John makes 9 and Larry makes 16 --> the answer to the question is 9
Fact 1 is SUFFICIENT

Fact 2: Larry assembled more chairs than John.

Here, we have 3 possibilities: John could have made 3, 6 or 9 chairs.
Fact 2 is INSUFFICIENT

Final Answer:

GMAT assassins aren't born, they're made,
Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

*****Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!*****

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/
Manager
Manager
avatar
Joined: 13 Aug 2012
Posts: 90
Re: Last Thursday, John assembled chairs at a rate of 3 chairs  [#permalink]

Show Tags

New post 06 Jan 2015, 09:53
GIVEN
John's Rate = 3 chairs/hour
Larry's Rate = 4 chairs/hour

In total both of them worked for 7 hours

STATEMENT 1
Let the amount of time John take be J and Larry take be L
Now, we're given that both of them on 2 days created a total of 25 chairs
so using the formula \(r*t=w\)
we get the following equation
\(3J + 4L = 25\)
\(J = \frac{(25 - 4l)}{3}\)
Only 2 pair of values satisfy this equation
\(L=1 and J=7\)
and
\(L=4 and J=3\)
we'll not consider the first equation since the total time they were given was 7 hours, but adding the those two values give us a total of 8
so the only other pair gives us the time, from which we can take out the no of chairs for both of them

Statement 2
Doesn't give us anything to solve for

Ans is A
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 11396
Re: Last Thursday, John assembled chairs at a rate of 3 chairs  [#permalink]

Show Tags

New post 08 Oct 2018, 12:37
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Bot
Re: Last Thursday, John assembled chairs at a rate of 3 chairs   [#permalink] 08 Oct 2018, 12:37
Display posts from previous: Sort by

Last Thursday, John assembled chairs at a rate of 3 chairs

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


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