A company has two types of machines, type R and type S. : PS Archive
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 17 Jan 2017, 11:44

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A company has two types of machines, type R and type S.

Author Message
SVP
Joined: 21 Jul 2006
Posts: 1538
Followers: 10

Kudos [?]: 741 [0], given: 1

A company has two types of machines, type R and type S.  [#permalink]

### Show Tags

07 Dec 2007, 05:30
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

A company has two types of machines, type R and type S. Operating at a constant rate, a machine of type R does a certain job in 36 hours and a machine of type S does the same job in 18 hours. If the company used the same number of each type of machine to do the job in 2 hours, how many machines of type R were used?

a) 3
b) 4
c) 6
d) 9
e) 12
VP
Joined: 08 Jun 2005
Posts: 1146
Followers: 7

Kudos [?]: 189 [1] , given: 0

### Show Tags

07 Dec 2007, 05:57
1
KUDOS
Type R = 1/36 of the job ---> In one hour
Type S = 1/18 of the job ---> In one hour

Type R = 2/36 of the job ---> In two hours
Type S = 2/18 of the job ---> In two hours

2/36+2/18 = 6/36 = 1/6

we will need six machines

Director
Joined: 26 Jul 2007
Posts: 541
Schools: Stern, McCombs, Marshall, Wharton
Followers: 7

Kudos [?]: 158 [0], given: 0

### Show Tags

07 Dec 2007, 07:47
KillerSquirrel wrote:
Type R = 1/36 of the job ---> In one hour
Type S = 1/18 of the job ---> In one hour

Type R = 2/36 of the job ---> In two hours
Type S = 2/18 of the job ---> In two hours

2/36+2/18 = 6/36 = 1/6

we will need six machines

I got the same as killer

R*T=W

(1/36x+1/18x)(2)=1
(x)(1/36+1/18)(2)=1
(x)(3/36)(2)=1
(x)(1/6)=1
x=6

Ans C
SVP
Joined: 21 Jul 2006
Posts: 1538
Followers: 10

Kudos [?]: 741 [0], given: 1

### Show Tags

07 Dec 2007, 07:56
OA is C
07 Dec 2007, 07:56
Display posts from previous: Sort by