Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
May 1308:30 AM PDT
-09:30 AM PDT
In Episode 4 of our GMAT Ninja CR series, we tackle the most intimidating CR question type: Boldface & "Legalese" questions. If you've ever stared at an answer choice that reads, "The first is a consideration introduced to counter a position that...
May 1212:00 PM EDT
-11:59 PM EDT
Make the most of your break with the most realistic GMAT™ prep. Take up to $700 off select products.- May 14
08:30 AM PDT
-09:30 AM PDT
Most GMAT test-takers are intimidated by the hardest GMAT Verbal questions. In this session, Target Test Prep GMAT instructor Erika Tyler-John, a 100th percentile GMAT scorer, will show you how top scorers break down challenging Verbal questions.. - Jun 10
06:00 AM PDT
-06:15 PM PDT
Register for the GMAT Club Virtual MBA Spotlight Fair – the world’s premier event for serious MBA candidates. This is your chance to hear directly from Admissions Directors at nearly every Top 30 MBA program..
14 Jun 2015, 13:48
Kudos
Bookmarks
Working alone at its constant rate, machine A produces \(x\) boxes in 10 minutes and working alone at its constant rate, machine B produces \(2x\) boxes in 5 minutes. How many minutes does it take machines A and B, working simultaneously at their respective constant rates, to produce \(3x\) boxes?
A. 3 minutes
B. 4 minutes
C. 5 minutes
D. 6 minutes
E. 12 minutes
A. 3 minutes
B. 4 minutes
C. 5 minutes
D. 6 minutes
E. 12 minutes
14 Jun 2015, 13:48
Kudos
Bookmarks
Official Solution:
Working alone at its constant rate, machine A produces \(x\) boxes in 10 minutes and working alone at its constant rate, machine B produces \(2x\) boxes in 5 minutes. How many minutes does it take machines A and B, working simultaneously at their respective constant rates, to produce \(3x\) boxes?
A. 3 minutes
B. 4 minutes
C. 5 minutes
D. 6 minutes
E. 12 minutes
The rate of machine \(A = \frac{job}{time} = \frac{x}{10}\) boxes per minute.
The rate of machine \(B = \frac{job}{time} = \frac{2x}{5}\) boxes per minute.
Their combined rate is \(\frac{x}{10} + \frac{2x}{5} = \frac{x}{2}\) boxes per minute.
To produce \(3x\) boxes, together they will need \(time = \frac{job}{combined \ rate} = \frac{3x}{(\frac{x}{2})} = 6 \ minutes\).
Answer: D
Working alone at its constant rate, machine A produces \(x\) boxes in 10 minutes and working alone at its constant rate, machine B produces \(2x\) boxes in 5 minutes. How many minutes does it take machines A and B, working simultaneously at their respective constant rates, to produce \(3x\) boxes?
A. 3 minutes
B. 4 minutes
C. 5 minutes
D. 6 minutes
E. 12 minutes
The rate of machine \(A = \frac{job}{time} = \frac{x}{10}\) boxes per minute.
The rate of machine \(B = \frac{job}{time} = \frac{2x}{5}\) boxes per minute.
Their combined rate is \(\frac{x}{10} + \frac{2x}{5} = \frac{x}{2}\) boxes per minute.
To produce \(3x\) boxes, together they will need \(time = \frac{job}{combined \ rate} = \frac{3x}{(\frac{x}{2})} = 6 \ minutes\).
Answer: D
