NutsAndBolts

Expert replies

shashank.ism: Legendary Member; Posts: 1022; Joined: Mon Jul 20, 2009 11:49 pmFollowed by: 2 members; Location: Gandhinagar; Thanked: 41 times

by shashank.ism » Tue Feb 09, 2010 7:24 am

In NutsAndBolts factory, one machine produces only nuts at the rate of 100 nuts per minute and needs to be cleaned for 5 minutes after production of every 1000 nuts. Another machine produces only bolts at the rate of 75 bolts per minute and needs to be cleaned for 10 minutes after production of every 1500 bolts. If both the machines start production at the same time, what is the minimum duration required for producing 9000 pairs of nuts and bolts?

130 minutes
135 minutes
170 minutes
180 minutes
200 minutes

My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.

Like this post

Source: Beat The GMAT — Problem Solving | Tue Feb 09, 2010 7:24 am

Osirus@VeritasPrep: GMAT Instructor; Posts: 1578; Joined: Thu May 28, 2009 8:02 amFollowed by: 34 members; Thanked: 128 times; GMAT Score:760

by Osirus@VeritasPrep » Tue Feb 09, 2010 12:21 pm

It would take 170 minutes.

Since bolts are produced at the slower rate, you only need to calculate how long it would take to produce 9000 bolts and include the time for breaks.

First, convert 75bolts per minute into 1500 bolts per hour. Next use the W = R X T formula. It would take divide 9000 by 4500 and you are left with 2 hours which translates to 120 minutes. However, you need to calculate how many breaks the machine would need. The machine needs to be cleaned for ten minutes for every 1500 bolts. Divide 9000 by 1500. The result is six, but one of these times would be after the job is done, so we don't calculate this break. So the machine must be cleaned for 10 minutes 5 times, which is 50 minutes. Add 50 mintutes to 120 and you arrive at your answer 170 minutes.

https://www.beatthegmat.com/the-retake-o ... 51414.html

Brandon Dorsey
GMAT Instructor
Veritas Prep

Buy any Veritas Prep book(s) and receive access to 5 Practice Cats for free! Learn More.

Like this post

komal: Legendary Member; Posts: 777; Joined: Fri Jan 01, 2010 4:02 amFollowed by: 47 members; Location: Mumbai, India; Thanked: 117 times

by komal » Tue Feb 16, 2010 11:43 am

shashank.ism wrote:In NutsAndBolts factory, one machine produces only nuts at the rate of 100 nuts per minute and needs to be cleaned for 5 minutes after production of every 1000 nuts. Another machine produces only bolts at the rate of 75 bolts per minute and needs to be cleaned for 10 minutes after production of every 1500 bolts. If both the machines start production at the same time, what is the minimum duration required for producing 9000 pairs of nuts and bolts?

130 minutes
135 minutes
170 minutes
180 minutes
200 minutes

Time taken in producing 9000 nuts

= 9000/100 Ã— 1 + 9000/1000 Ã— 5

= 90 + 45 = 135 minutes

Time taken in producing 9000 bolts

= 9000/75 Ã— 1 + 9000/1500 Ã— 10

= 120 + 60 = 180 minutes

Thus for making 9000 pairs of nuts and bolts time taken is 180 minutes.

https://www.e-gmat.com/

Like this post

ajith: Legendary Member; Posts: 1275; Joined: Thu Sep 21, 2006 11:13 pmFollowed by: 2 members; Location: Arabian Sea; Thanked: 125 times

by ajith » Tue Feb 16, 2010 2:07 pm

komal wrote: Time taken in producing 9000 nuts

= 9000/100 Ã— 1 + 9000/1000 Ã— 5

= 90 + 45 = 135 minutes

Time taken in producing 9000 bolts

= 9000/75 Ã— 1 + 9000/1500 Ã— 10

= 120 + 60 = 180 minutes

Thus for making 9000 pairs of nuts and bolts time taken is 180 minutes

The time taken for producing a lot of 1500 bolts is 20 minutes
after that there is a 10 minutes break

it takes 6 lots of 1500 to make it 9000
we need 5 breaks in between these lots
time taken = 6*20+50 = 170 as Osirus mentioned

Always borrow money from a pessimist, he doesn't expect to be paid back.

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review