Last visit was: 11 Jul 2025, 05:13 It is currently 11 Jul 2025, 05:13
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
505-555 Level|   Word Problems|                                          
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 11 Jul 2025
Posts: 102,634
Own Kudos:
Given Kudos: 98,170
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,634
Kudos: 740,340
 [34]
1
Kudos
Add Kudos
33
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 11 Jul 2025
Posts: 102,634
Own Kudos:
Given Kudos: 98,170
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,634
Kudos: 740,340
 [16]
7
Kudos
Add Kudos
9
Bookmarks
Bookmark this Post
General Discussion
User avatar
WoundedTiger
Joined: 25 Apr 2012
Last visit: 25 Sep 2024
Posts: 523
Own Kudos:
2,479
 [2]
Given Kudos: 740
Location: India
GPA: 3.21
WE:Business Development (Other)
Products:
Posts: 523
Kudos: 2,479
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
arunspanda
Joined: 04 Oct 2013
Last visit: 31 Oct 2021
Posts: 127
Own Kudos:
321
 [2]
Given Kudos: 55
Location: India
GMAT Date: 05-23-2015
GPA: 3.45
Products:
Posts: 127
Kudos: 321
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
On Monday morning a certain machine ran continuously at a uniform rate to fill a production order. At what time did it completely fill the order that morning?

(1) The machine began filling the order at 9:30 a.m.
(2) The machine had filled 1/2 of the order by 10:30 a.m. and 5/6 to the order by 11:10 a.m.



Statement 1

In order to find the time when machine would completely fill the order, we need the following data:
a. Start time or any other time as reference
b. Rate to fill the order

Since, statement (1) does not provide Rate, the statement 1 alone is not sufficient.........(A) (D)

Statement 2

Rate of filling by machine \(= (\frac{5}{6} -\frac{1}{2})\)/Time interval\(= 1/3\) per\(40\) minutes

Given that, 5/6 of the order was filled by 11:10 a.m., the remaining 1/6 of the order would take 20 minutes more. So, the complete order was filled by 11:30 a.m.....Sufficient....(C) (E)

Answer: (B)
User avatar
stne
Joined: 27 May 2012
Last visit: 08 Jul 2025
Posts: 1,767
Own Kudos:
Given Kudos: 656
Posts: 1,767
Kudos: 1,836
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
On Monday morning a certain machine ran continuously at a uniform rate to fill a production order. At what time did it completely fill the order that morning?

(1) The machine began filling the order at 9:30 a.m.
(2) The machine had filled 1/2 of the order by 10:30 a.m. and 5/6 to the order by 11:00 a.m.




There is a typo in the above question, it should be 11:10 AM and not 11:00 AM

1) Insufficient as we do not know the rate

2) We can see that 1/3 of the work was done in 40 minutes, therefore whole whole work was done in 120 minutes or 2 hours ,Since half of the work would be done in 1 hour , so by 10:30, half of the work was done, another half work would take another hour, so by 11:30 the work was completed.
Sufficient
Answer B
avatar
mrslee
Joined: 10 Sep 2013
Last visit: 09 Nov 2015
Posts: 60
Own Kudos:
5
 [1]
Given Kudos: 25
Concentration: General Management, Finance
GPA: 3.9
Posts: 60
Kudos: 5
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
SOLUTION

On Monday morning a certain machine ran continuously at a uniform rate to fill a production order. At what time did it completely fill the order that morning?

(1) The machine began filling the order at 9:30 a.m. Clearly insufficient.

(2) The machine had filled 1/2 of the order by 10:30 a.m. and 5/6 to the order by 11:10 a.m.

In 40 minutes from 10:30 a.m. to 11:10 a.m., 5/6 - 1/2 = 1/3 of the job was done. Thus to do the entire job 3*40 minutes = 120 minutes = 2 hours are needed. Since by 10:30 a.m. half of the job was done, therefore for another half 1 more hour is needed. Therefore the entire job was done by 11:30 a.m. Sufficient.

Answer: B.


Why cant we solve in this fashion?
If the half of job is done by 10.30, another half will be 1+ hour . So 10.30 + 1 = 11.30 ,hm?
User avatar
ScottTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 14 Oct 2015
Last visit: 10 Jul 2025
Posts: 21,070
Own Kudos:
Given Kudos: 296
Status:Founder & CEO
Affiliations: Target Test Prep
Location: United States (CA)
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 21,070
Kudos: 26,130
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
The Official Guide For GMAT® Quantitative Review, 2ND Edition

On Monday morning a certain machine ran continuously at a uniform rate to fill a production order. At what time did it completely fill the order that morning?

(1) The machine began filling the order at 9:30 a.m.
(2) The machine had filled 1/2 of the order by 10:30 a.m. and 5/6 to the order by 11:10 a.m.

Solution:

We are given that a certain machine ran continuously at uniform rate to fill a production order. We need to determine at what time it filled the order.

Statement One Alone:

The machine began filling the order at 9:30 a.m.

Only knowing what time the machine began filling the order is not enough information to determine at what time the order was completely filled. Statement one alone is not sufficient to answer the question.

Statement Two Alone:

The machine had filled 1/2 of the order by 10:30 a.m. and 5/6 of the order by 11:10 a.m.

Using the information in statement two, we can determine that the machine completed 5/6 - 1/2 = 5/6 - 3/6 = 2/6 = 1/3 of the job in 40 minutes. Since rate = work/time, the rate of the machine is (1/3)/40 = 1/120. We can now determine how many minutes it would take the machine to complete the remaining 1/6 of the job.

time = work/rate

time = (1/6)/(1/120) = 120/6 = 20 minutes.

Thus, the machine needs 20 more minutes to complete the remaining 1/6 of the job. That is, the machine completes the entire job at 11:30 a.m.

Answer: B
User avatar
fskilnik
Joined: 12 Oct 2010
Last visit: 03 Jan 2025
Posts: 885
Own Kudos:
1,693
 [1]
Given Kudos: 57
Status:GMATH founder
Expert
Expert reply
Posts: 885
Kudos: 1,693
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
On Monday morning a certain machine ran continuously at a uniform rate to fill a production order. At what time did it completely fill the order that morning?

(1) The machine began filling the order at 9:30 a.m.
(2) The machine had filled 1/2 of the order by 10:30 a.m. and 5/6 of the order by 11:10 a.m.

Although a careful reading guarantees choosing the right answer without ANY need of writing,
let´s use this easy problem to practice UNITS CONTROL, one of our method´s most powerful tools!

\(?\,\,:\,\,{\text{time}}\,\,{\text{it}}\,\,{\text{finished}}\,\,{\text{the}}\,\,{\text{order}}\)

\(\left( 1 \right)\,\,{\text{If}}\,\,{\text{it}}\,\,\left\{ \begin{gathered}\\
{\text{takes}}\,\,30\min \,\,\, \Rightarrow \,\,\,? = 10\,\,{\text{a}}{\text{.m}}{\text{.}} \hfill \\\\
{\text{takes}}\,\,90\min \,\,\, \Rightarrow \,\,\,? = 11\,\,{\text{a}}{\text{.m}}{\text{.}} \hfill \\ \\
\end{gathered} \right.\)

\(\left( 2 \right)\,\,\, \Rightarrow \,\,\frac{{\,\,\left( {\frac{5}{6} - \frac{1}{2} = } \right)\,\,\,\frac{1}{3}\,\,{\text{order}}\,\,}}{{40\,\,\min }}\)

\(\frac{1}{2}\,\,{\text{order}}\,\,\left( {\frac{{40\,\,\min }}{{\frac{1}{3}\,\,{\text{order}}}}} \right) = 60\,\,\min \,\,\,\left( {{\text{for}}\,\,{\text{half - order}}} \right)\,\,\)

\(?\,\, = \,\,10{\text{h}}30\min + 60\min \,\,\,\, \Rightarrow \,\,\,\,{\text{SUFF}}.\)


This solution follows the notations and rationale taught in the GMATH method.

Regards,
fskilnik.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 37,374
Own Kudos:
Posts: 37,374
Kudos: 1,010
Kudos
Add Kudos
Bookmarks
Bookmark this Post
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.
Moderator:
Math Expert
102634 posts