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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

While working alone at their constant rates computer X can process 240 [#permalink]

Show Tags

29 Mar 2011, 04:36

7

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

5% (low)

Question Stats:

86% (00:54) correct
14% (01:34) wrong based on 316 sessions

HideShow timer Statistics

While working alone at their constant rates computer X can process 240 files in 4 hours, and comp Y 240 files in 8 hrs. If all files processed by these comp. are the same size how long would it take the two comp. working at the same time at their respective constant rates , to process a total of 240 files?

A. 2hrs B. 2hrs 20 min C. 2hrs 40 min D. 6hrs E. 6hrs 20 min

i did as under X in one hour = 240/4 = 60 files Y in one hour = 240/8 = 30 fles X+ Y in one hour 60+30=90 files So together they will take (240/90)= 2 hours 40 minutes. So C is the answer. I do not know the OA. Am I right?

Re: While working alone at their constant rates computer X can process 240 [#permalink]

Show Tags

29 Mar 2011, 05:14

Baten80 wrote:

While working alone at their constant rates computer X can process 240 files in 4 hours, and comp Y 240 files in 8 hrs. If all files processed by these comp. are the same size how long would it take the two comp. working at the same time at their respective constant rates , to process a total of 240 files?

2hrs 2hrs 20 min 2hrs 40 min 6hrs 6hrs 20 min

i did as under X in one hour = 240/4 = 60 files Y in one hour = 240/8 = 30 fles X+ Y in one hour 60+30=90 files So together they will take (240/90)= 2 hours 40 minutes. So C is the answer. I do not know the OA. Am I right?

Computer 1 processes 60 files an hour Computer 2 processes 30 files an hour

Combined they will process 90 files an hour

For 240 files, they will take (240/9) hours ... which is 2h40m
_________________

Re: While working alone at their constant rates computer X can process 240 [#permalink]

Show Tags

29 Mar 2011, 05:47

Baten80 wrote:

While working alone at their constant rates computer X can process 240 files in 4 hours, and comp Y 240 files in 8 hrs. If all files processed by these comp. are the same size how long would it take the two comp. working at the same time at their respective constant rates , to process a total of 240 files?

2hrs 2hrs 20 min 2hrs 40 min 6hrs 6hrs 20 min

i did as under X in one hour = 240/4 = 60 files Y in one hour = 240/8 = 30 fles X+ Y in one hour 60+30=90 files So together they will take (240/90)= 2 hours 40 minutes. So C is the answer. I do not know the OA. Am I right?

Re: While working alone at their constant rates computer X can process 240 [#permalink]

Show Tags

06 Apr 2011, 07:25

X - 60 files per hour Y - 30 files per hour X & Y together - 90 files per hour 90+90=180 We need 60 more So 60/90 of an hour i.e. 2/3 of an hour = 40 min So 2 hours and 40 min...

While working alone at their constant rates computer X can process 240 files in 4 hours, and comp Y 240 files in 8 hrs. If all files processed by these comp. are the same size how long would it take the two comp. working at the same time at their respective constant rates , to process a total of 240 files?

A. 2hrs B. 2hrs 20 min C. 2hrs 40 min D. 6hrs E. 6hrs 20 min

The rate of computer X is 240/4 = 60 files in 1 hour and the rate of computer Y is 240/8 = 30 files in 1 hour, so the combined rate is 90 files in 1 hour. Thus, it takes 240/90 = 2 60/90 hours = 2 ⅔ hours = 2 hours and 40 minutes to complete 240 files when both computers work together.

Answer: C
_________________

Scott Woodbury-Stewart Founder and CEO

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