Work problem

Expert replies

bobdylan: Senior | Next Rank: 100 Posts; Posts: 68; Joined: Wed Nov 30, 2011 3:12 pm

by bobdylan » Wed Jun 06, 2012 5:11 am

Working alone, printing presses A,B and C can fill the daily allotment of newspapers in 8,10, and 12 hours, respectively. What is the ratio of the time it takes press A to fill the allotment working alone to the time it takes presses B and C to fill the allotment together at their respective rates?

a) 11:4
b) 22:15
c) 15:22
d) 4:11
e)1:11

Like this post

Source: Beat The GMAT — Problem Solving | Wed Jun 06, 2012 5:11 am

Ashujain: Master | Next Rank: 500 Posts; Posts: 123; Joined: Fri Apr 20, 2012 4:36 amFollowed by: 1 member; Thanked: 29 times

by Ashujain » Wed Jun 06, 2012 5:39 am

bobdylan wrote:Working alone, printing presses A,B and C can fill the daily allotment of newspapers in 8,10, and 12 hours, respectively. What is the ratio of the time it takes press A to fill the allotment working alone to the time it takes presses B and C to fill the allotment together at their respective rates?

a) 11:4
b) 22:15
c) 15:22
d) 4:11
e)1:11

Time taken by B and C working simultaneously = 1/(1/B+1/C) = 1/(1/10+1/12) = 60/11

Therefore, 8*11/60 = 22/15

Like this post

GMATGuruNY: GMAT Instructor; Posts: 15539; Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members; Location: New York, NY; Thanked: 13060 times; GMAT Score:790

by GMATGuruNY » Wed Jun 06, 2012 6:38 am

bobdylan wrote:Working alone, printing presses A,B and C can fill the daily allotment of newspapers in 8,10, and 12 hours, respectively. What is the ratio of the time it takes press A to fill the allotment working alone to the time it takes presses B and C to fill the allotment together at their respective rates?

a) 11:4
b) 22:15
c) 15:22
d) 4:11
e)1:11

Let the allotment = 60 units.
Rate for B alone = 60/10 = 6 units per hour.
Rate for C alone = 60/12 = 5 units per hour.
Combined rate for B+C = 6+5 = 11 units per hour.
Time for B+C together = 60/11.
(time for A)/(time for B+C) = 8/(60/11) = 88/60 = 22/15.

The correct answer is B.

Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

559 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review