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 0808:00 AM PDT
-08:30 AM PDT
Join the special YouTube live-stream for selecting the winners of GMAT Club MBA Scholarships sponsored by Juno live. Watch who gets these coveted MBA scholarships offered by GMAT Club and Juno.
07 Aug 2019, 03:45
Kudos
Bookmarks
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
15%
(low)
Question Stats:
82% (02:09) correct
18%
(02:48)
wrong
based on 192
sessions
History
Date
Time
Result
Not Attempted Yet
A new copy machine can run off 1,500 workbooks in 8 hours, while it takes on older copy machine 12 hours to do the same job. What is the total number of hours that it would take both copy machines working at the same time, but independently, to run off the 1,500 workbooks?
(A) 4.4
(B) 4.6
(C) 4.8
(D) 5
(E) 10
(A) 4.4
(B) 4.6
(C) 4.8
(D) 5
(E) 10
firas92
Current Student
Joined: 16 Jan 2019
Last visit: 02 Dec 2024
Posts: 616
Given Kudos: 142
Location: India
Concentration: General Management
Schools: Tepper '23 (M$) Foster '23 (D)
GMAT 1: 740 Q50 V40
WE:Sales (Other)
Products:
07 Aug 2019, 04:01
Kudos
Bookmarks
Work rate of new copier \(= \frac{1500}{8} = \frac{375}{2}\)
Work rate of old copier \(= \frac{1500}{12} = \frac{250}{2}\)
Combined work rate \(= \frac{375}{2}+\frac{250}{2}=\frac{625}{2}\)
So we have
\(\frac{625}{2}*hours=1500\)
Hours\(=\frac{1500*2}{625}=4.8\)
Answer is (C)
Posted from my mobile device
Work rate of old copier \(= \frac{1500}{12} = \frac{250}{2}\)
Combined work rate \(= \frac{375}{2}+\frac{250}{2}=\frac{625}{2}\)
So we have
\(\frac{625}{2}*hours=1500\)
Hours\(=\frac{1500*2}{625}=4.8\)
Answer is (C)
Posted from my mobile device
07 Aug 2019, 04:16
Kudos
Bookmarks
as all the work done by both machines and the combined rate work is same treat 1500 copies as 1 work
so new m/C 1 work in 8 hrs
so in 1 hr -------------1/8 work
similarly for old M/C
1hr----------------1/12 work
net work by both m/c in 1 hr = 1/8+1/12= 20/96
so time taken will be 96/20 hrs to complete one work therefore 1500 copies
=4.8 hrs
C
so new m/C 1 work in 8 hrs
so in 1 hr -------------1/8 work
similarly for old M/C
1hr----------------1/12 work
net work by both m/c in 1 hr = 1/8+1/12= 20/96
so time taken will be 96/20 hrs to complete one work therefore 1500 copies
=4.8 hrs
C
