• Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh
  • e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep

At this rate, how many bolts could 4 such machines produce..

This topic has 4 expert replies and 0 member replies

At this rate, how many bolts could 4 such machines produce..

Post Tue Sep 12, 2017 11:00 am
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

The OA is E.

I am very confuse here. Who is "a"? and why is E?

  • +1 Upvote Post
  • Quote
  • Flag
Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!

GMAT/MBA Expert

Top Reply
Post Wed Sep 20, 2017 2:43 pm
Vincen 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.

Answer: E

_________________

Scott Woodbury Stewart Founder & CEO
GMAT Quant Self-Study Course - 500+ lessons 3000+ practice problems 800+ HD solutions
5-Day Free Trial 5-DAY FREE, FULL-ACCESS TRIAL TTP QUANT

  • +1 Upvote Post
  • Quote
  • Flag
Thanked by: Vincen
Top Reply
Post Tue Sep 12, 2017 2:36 pm
Vincen 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
Let a=1, implying that 1 machine produces 120 bolts per minute.
Since 1 machine produces 120 bolts per minute, the rate for 4 machines = 4*120 = 480 bolts per minute.
At a rate of 480 bolts per minute, the number of bolts produced by the 4 machines in 5 minutes = rt = 480*5 = 2400 bolts. This is our target.

Now plug a=1 into the answer choices to see which yield the target value of 2400.
Only E works:
2400/a = 2400/1 = 2400.

The correct answer is E.

_________________
Mitch Hunt
GMAT Private Tutor
GMATGuruNY@gmail.com
If you find one of my posts helpful, please take a moment to click on the "Thank" icon.
Available for tutoring in NYC and long-distance.
For more information, please email me at GMATGuruNY@gmail.com.

  • +1 Upvote Post
  • Quote
  • Flag
Thanked by: Vincen
Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now.

GMAT/MBA Expert

Post Wed Sep 20, 2017 2:43 pm
Vincen 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.

Answer: E

_________________

Scott Woodbury Stewart Founder & CEO
GMAT Quant Self-Study Course - 500+ lessons 3000+ practice problems 800+ HD solutions
5-Day Free Trial 5-DAY FREE, FULL-ACCESS TRIAL TTP QUANT

  • +1 Upvote Post
  • Quote
  • Flag
Thanked by: Vincen
Post Tue Sep 12, 2017 2:36 pm
Vincen 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
Let a=1, implying that 1 machine produces 120 bolts per minute.
Since 1 machine produces 120 bolts per minute, the rate for 4 machines = 4*120 = 480 bolts per minute.
At a rate of 480 bolts per minute, the number of bolts produced by the 4 machines in 5 minutes = rt = 480*5 = 2400 bolts. This is our target.

Now plug a=1 into the answer choices to see which yield the target value of 2400.
Only E works:
2400/a = 2400/1 = 2400.

The correct answer is E.

_________________
Mitch Hunt
GMAT Private Tutor
GMATGuruNY@gmail.com
If you find one of my posts helpful, please take a moment to click on the "Thank" icon.
Available for tutoring in NYC and long-distance.
For more information, please email me at GMATGuruNY@gmail.com.

  • +1 Upvote Post
  • Quote
  • Flag
Thanked by: Vincen
Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now.

Best Conversation Starters

1 lheiannie07 116 topics
2 LUANDATO 67 topics
3 swerve 66 topics
4 ardz24 61 topics
5 AAPL 59 topics
See More Top Beat The GMAT Members...

Most Active Experts

1 image description Scott@TargetTestPrep

Target Test Prep

213 posts
2 image description Brent@GMATPrepNow

GMAT Prep Now Teacher

177 posts
3 image description Jeff@TargetTestPrep

Target Test Prep

168 posts
4 image description Rich.C@EMPOWERgma...

EMPOWERgmat

133 posts
5 image description GMATGuruNY

The Princeton Review Teacher

126 posts
See More Top Beat The GMAT Experts