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 Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

It takes 6 technicians a total of 10 hours to build and [#permalink]
12 Apr 2010, 04:41

3

This post received KUDOS

8

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

65% (hard)

Question Stats:

63% (03:25) correct
37% (02:26) wrong based on 536 sessions

It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each working at the same rate. If six technicians start to build the server at 11:00 AM, and one technician per hour is added beginning at 5:00 PM, at what time will the server be complete?

A. 7:30 PM B. 7:45 PM C. 8:00 PM D. 9:00 AM E. 10:00 PM

Re: Work Rate Problem [#permalink]
12 Apr 2010, 06:20

13

This post received KUDOS

2

This post was BOOKMARKED

Ans: C

6Techs can complete the job in 10 hours. 6 Techs can do 1/10 job in 1 hour 1 Tech can do 1/(6*10) = 1/60 job in 1 hour.

Now 6 techs worked from 11.00Am tp 5.00PM means they worked for 6 hours. 6Techs worked for 6 hours = 6/10 job completed. From 5.00 PM to 6.00 Pm a tech is added, so 7 Techs worked for 1 hour = 7/60 job Total job completed at 6.00PM is = 6/10+7/60 = 43/60 job done.

From 6.00 PM to 7.00 Pm a tech is added, so 8 Techs worked for 1 hour = 8/60 job Total job completed at 7.00PM is = 43/60 + 8/60 = 51/60 job done.

From 7.00 PM to 8.00 Pm a tech is added, so 9 Techs worked for 1 hour = 9/60 job Total job completed at 7.00PM is = 51/60 + 9/60 = 60/60 job done. Job is COMPLETE.

Job is complete at 8.00PM. The total number of hours is 9 hours. _________________

Re: Work Rate Problem [#permalink]
12 Apr 2010, 06:22

42

This post received KUDOS

Expert's post

1

This post was BOOKMARKED

Hussain15 wrote:

It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each working at the same rate. If six technicians start to build the server at 11:00 AM, and one technician per hour is added beginning at 5:00 PM, at what time will the server be complete?

A. 7:30 PM B. 7:45 PM C. 8:00 PM D. 9:00 AM E. 10:00 PM

To complete the job 6*10=60 man/hours are needed. By 5:00 PM 6*6=36 man/hour done. 24 is left.

Re: It takes 6 technicians a total of 10 hours to build and [#permalink]
13 Jun 2013, 18:45

This is how I approach it: Because 6 men started at 11am and the addition of another man occurs after 5. Therefore, the amount of work done by 5pm will be = (1/10)X(17-11)= 6/10 The remaining work will thus be = 4/10

Re: It takes 6 technicians a total of 10 hours to build and [#permalink]
28 Jun 2013, 19:12

Hussain15 wrote:

It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each working at the same rate. If six technicians start to build the server at 11:00 AM, and one technician per hour is added beginning at 5:00 PM, at what time will the server be complete?

A. 7:30 PM B. 7:45 PM C. 8:00 PM D. 9:00 AM E. 10:00 PM

We should never, everrr make questions too complicated to infer and solve... 6 tech total of 10 hours... let me assume total of 60 units of work... 1 tech in 1 hr does 1 unit of work.....

11:00 am to 5:pm - 6 hours so, total work done by 6 tech in 6 hrs will be 36 unit. ( 6*6) now a new person gets added every hour after 5:00PM

11:00-5:00 - 36 unit 5:00-6:00 - 7 unit ( 6 tech were doing 6 unit in 1 hr, now since a new person has been added, the work increases to 7 unit) 6:00-7:00 - 8 unit ( another guy added) 7:00-8:00- 9 unit ( another guys added making total 9 person in the work field)

36+7+8+9 = 60.

so by 8:00PM 60 units of work was completed by the group....

Re: It takes 6 technicians a total of 10 hours to build and [#permalink]
29 Jun 2013, 03:50

Hussain15 wrote:

It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each working at the same rate. If six technicians start to build the server at 11:00 AM, and one technician per hour is added beginning at 5:00 PM, at what time will the server be complete?

A. 7:30 PM B. 7:45 PM C. 8:00 PM D. 9:00 AM E. 10:00 PM

1. Originally 6 people work for 60 man hours 2. Additional people work for 6 man hours 3. So to complete the same task since the same man hours is taken , the original 6 people work for 6 man hours less. i.e., they work for 60-6=54 man hours i.e., they work for 9 hours each 4 . In other words if they start the task at 11 A.M , they complete the task at 8:00 PM

Re: Work Rate Problem [#permalink]
17 Aug 2013, 02:52

Bunuel wrote:

Hussain15 wrote:

It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each working at the same rate. If six technicians start to build the server at 11:00 AM, and one technician per hour is added beginning at 5:00 PM, at what time will the server be complete?

A. 7:30 PM B. 7:45 PM C. 8:00 PM D. 9:00 AM E. 10:00 PM

To complete the job 6*10=60 man/hours are needed. By 5:00 PM 6*6=36 man/hour done. 24 is left.

Makes me giggle how Bunuel always finds a simple yet understood solution! Though first I struggle to understand the problem and the previous posters' solutions! Thanks Bunuel!

Re: It takes 6 technicians a total of 10 hours to build and [#permalink]
17 Aug 2013, 03:38

Hussain15 wrote:

It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each working at the same rate. If six technicians start to build the server at 11:00 AM, and one technician per hour is added beginning at 5:00 PM, at what time will the server be complete?

A. 7:30 PM B. 7:45 PM C. 8:00 PM D. 9:00 AM E. 10:00 PM

6man, 10 hours = 1 full work 6 hours = 3/5 work done. due = 1- 3/5 = 2/5

6 men 10 hours so 7 men 60/7 hours to complete a job

so, 7 men 1 hour = 7/60 8 men 1 hour = 8/60 9 men 1 hour = 9/60 .......................................... + 3 hours = 24/60 = 2/5 parts of total works.

Re: It takes 6 technicians a total of 10 hours to build and [#permalink]
25 Sep 2013, 21:03

Man * Days * hours = Work done

6 people * 10 hours = 60 units

6 people * (11AM to 5 PM) 6 hours = 36

Work left 60-36 = 24

5-6 : 7 people = 7 units 6-7 : 8 people = 8 units 7-8: 9 people = 9 units Total = 24 units

hence 8PM _________________

Rgds, TGC! _____________________________________________________________________ I Assisted You => KUDOS Please _____________________________________________________________________________

Re: It takes 6 technicians a total of 10 hours to build and [#permalink]
20 Nov 2013, 09:23

Hussain15 wrote:

It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each working at the same rate. If six technicians start to build the server at 11:00 AM, and one technician per hour is added beginning at 5:00 PM, at what time will the server be complete?

A. 7:30 PM B. 7:45 PM C. 8:00 PM D. 9:00 AM E. 10:00 PM

Can someone explain how this fits into the standard w=r*t formula? I feel like that learning that formula was useless, because every time I try and apply it to one of these problems, it's wrong.

"It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each working at the same rate. If six technicians start to build the server at 11:00 AM, and one technician per hour is added beginning at 5:00 PM, at what time will the server be complete?"

I tried this: If the rate of a technician is \frac{1}{T}, and you have 6 technicians working from 9-5, then their hourly rate should be 6/T, so using w=r*t w=8*\frac{6}{t}, so W=\frac{48}{T}. But then what do I do after that?

Re: It takes 6 technicians a total of 10 hours to build and [#permalink]
24 Dec 2013, 12:14

1

This post received KUDOS

Hussain15 wrote:

It takes 6 technicians a total of 10 hours to build and program a new server from Direct Computer, with each working at the same rate. If six technicians start to build the server at 11:00 AM, and one technician per hour is added beginning at 5:00 PM, at what time will the server be complete?

A. 7:30 PM B. 7:45 PM C. 8:00 PM D. 9:00 AM E. 10:00 PM

So we need 60 hours men to finish the work 6 technitians will work for 6 hours hence they will do 36 hours. We now have 24 hours men left to complete At 6pm - 7 hours men = 24 - 7 = 17 At 7pm - 8 hours men= 17-8 = 9 At 8pm- 9 hours men = Job Done

Hence answer is (C)

Hope it helps Cheers! J

gmatclubot

Re: It takes 6 technicians a total of 10 hours to build and
[#permalink]
24 Dec 2013, 12:14

I couldn’t help myself but stay impressed. young leader who can now basically speak Chinese and handle things alone (I’m Korean Canadian by the way, so...