It is currently 18 Feb 2018, 22:11

### 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

# Running at the same constant rate, a identical machines

Author Message
TAGS:

### Hide Tags

Moderator
Joined: 29 Jan 2015
Posts: 634
Location: India
WE: General Management (Non-Profit and Government)
Running at the same constant rate, a identical machines [#permalink]

### Show Tags

28 May 2017, 06:22
1
KUDOS
3
This post was
BOOKMARKED
00:00

Difficulty:

15% (low)

Question Stats:

81% (00:57) correct 19% (01:26) wrong based on 102 sessions

### HideShow timer Statistics

Running at the same constant rate, a identical machines can produce a total of 120 bolts per minute. At this rate, how many bolts could 4 such machines produce in 5 minutes?

(A) a/6
(B) a/600
(C) 150/a
(D) 480/a
(E) 2,400/a
[Reveal] Spoiler: OA

_________________

If you liked my post, kindly give me a Kudos. Thanks.

Director
Joined: 04 Dec 2015
Posts: 696
Location: India
Concentration: Technology, Strategy
Schools: ISB '19, IIMA , IIMB, XLRI
WE: Information Technology (Consulting)
Re: Running at the same constant rate, a identical machines [#permalink]

### Show Tags

28 May 2017, 08:03
rohan2345 wrote:
Running at the same constant rate, a identical machines can produce a total of 120 bolts per minute. At this rate, how many bolts could 4 such machines produce in 5 minutes?

(A) a/6
(B) a/600
(C) 150/a
(D) 480/a
(E) 2,400/a

"a" identical machines can produce 120 bolts per minute.
In 5 mins "a" machines can produce = 120 x 5 = 600 bolts

Therefore number of bolts produced by 4 such machines = $$\frac{600 * 4}{a}$$ = $$\frac{2400}{a}$$
DS Forum Moderator
Joined: 21 Aug 2013
Posts: 783
Location: India
Re: Running at the same constant rate, a identical machines [#permalink]

### Show Tags

28 May 2017, 10:07
'a' machines in 1 minute = 120 bolts
'a' machines in 4 minutes = 5*120 = 600 bolts

This is a direct variation between number of bolts and number of machines. (greater the number of machines, greater the number of bolts produced)
Let bolts produced by 4 such machines be 'x'

So we have a/4 = 600/x Or x = 2400/a

VP
Joined: 22 May 2016
Posts: 1329
Running at the same constant rate, a identical machines [#permalink]

### Show Tags

28 May 2017, 14:31
rohan2345 wrote:
Running at the same constant rate, a identical machines can produce a total of 120 bolts per minute. At this rate, how many bolts could 4 such machines produce in 5 minutes?

(A) a/6
(B) a/600
(C) 150/a
(D) 480/a
(E) 2,400/a

1. Find INDIVIDUAL RATE:

W / (# of workers * time) = individual rate

120 / a*1 = 120/a

2. How many bolts produced by 4 machines in 5 minutes?

Find TOTAL WORK given new # of machines and new time:

(# of workers) * (individual rate) * (time) = total work

4 * 120/a * 5 = 2400/a

_________________

At the still point, there the dance is. -- T.S. Eliot
Formerly genxer123

Last edited by generis on 29 Aug 2017, 09:47, edited 1 time in total.
EMPOWERgmat Instructor
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 11025
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Re: Running at the same constant rate, a identical machines [#permalink]

### Show Tags

29 May 2017, 17:51
1
KUDOS
Expert's post
Hi rohan2345,

This question can be solved by TESTing VALUES.

We're told that a total of A machines (working together) will produce 120 bolts/minute. We're asked for the number of bolts that could be produced by 4 of these machines in 5 minutes.

IF... A=2
Then 2 machines will produce those 120 total bolts/minute. Thus....
4 machines will produce 240 bolts/minute.
In 5 minutes, those 4 machines will produce (5)(240) = 1200 bolts

So we're looking for an answer that equals 1200 when A=2. There's only one answer that 'fits'...

[Reveal] Spoiler:
E

GMAT assassins aren't born, they're made,
Rich
_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

# Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save \$75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************

Math Expert
Joined: 02 Sep 2009
Posts: 43803
Re: Running at the same constant rate, a identical machines [#permalink]

### Show Tags

29 Aug 2017, 09:16
Nunuboy1994 wrote:
EMPOWERgmatRichC wrote:
Hi rohan2345,

This question can be solved by TESTing VALUES.

We're told that a total of A machines (working together) will produce 120 bolts/minute. We're asked for the number of bolts that could be produced by 4 of these machines in 5 minutes.

IF... A=2
Then 2 machines will produce those 120 total bolts/minute. Thus....
4 machines will produce 240 bolts/minute.
In 5 minutes, those 4 machines will produce (5)(240) = 1200 bolts

So we're looking for an answer that equals 1200 when A=2. There's only one answer that 'fits'...

[Reveal] Spoiler:
E

GMAT assassins aren't born, they're made,
Rich
EMPOWERgmatRichC Doesn't this problem belong in the work rate section?

______________________
Edited the tags. Thank you.
_________________
Intern
Status: Never Say Never
Joined: 27 May 2014
Posts: 48
Location: India
GMAT 1: 640 Q46 V32
GMAT 2: 670 Q49 V33
GPA: 3.89
WE: Information Technology (Computer Software)
Re: Running at the same constant rate, a identical machines [#permalink]

### Show Tags

29 Aug 2017, 09:21
1
KUDOS
easier to get confused without the appropriate highlight in the question part -
Running at the same constant rate, a identical machines can produce a total of 120 bolts per minute.

a machines -> 120
1 machine -> 120/a
4 machines -> (120*4)/a

above is all per minute, so for 5 minutes -
(120*4*5)/a = 2400/a

E
_________________

never say never !
-Give a kudos if my answer helped you.

Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 1975
Re: Running at the same constant rate, a identical machines [#permalink]

### Show Tags

01 Sep 2017, 11:00
rohan2345 wrote:
Running at the same constant rate, a identical machines can produce a total of 120 bolts per minute. At this rate, how many bolts could 4 such machines produce in 5 minutes?

(A) a/6
(B) a/600
(C) 150/a
(D) 480/a
(E) 2,400/a

We are given that the rate of a machines is 120. Thus, the rate of 4 machines is:

a/120 = 4/x

ax = 480

x = 480/a

Since the rate of 4 machines is 480/a bolts per minute, 4 machines can produce 480/a * 5 = 2400/a bolts in 5 minutes.

_________________

Jeffery Miller

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

Re: Running at the same constant rate, a identical machines   [#permalink] 01 Sep 2017, 11:00
Display posts from previous: Sort by