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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

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:

Let M=Men, D=Days, H=Hours, W=Work M ∝ W (M is directly proportional to W) D ∝ W H ∝ W MDH ∝ W MDH = kW MDH/W = k I know MDH represents Total Men hour work and W represents 1 unit of work. Then what does the ratio MDH/W represents.

Let M=Men, D=Days, H=Hours, W=Work M ∝ W (M is directly proportional to W) D ∝ W H ∝ W MDH ∝ W MDH = kW MDH/W = k I know MDH represents Total Men hour work and W represents 1 unit of work. Then what does the ratio MDH/W represents.

Dear 22990atinesh, I'm happy to respond.

First of all, I'll suggest that if you put the k on the other side of the equation, it will be much more sensible: kMDH = W So that k = W/(MDH) which would make it vaguely rate-like. Work per man-hour-days, something like that.

I will say, I don't think know this formula is going to help you on the GMAT. You do have to know the basic idea of work rate R, where A = RT (A is the amount of work done). The GMAT tends not to ask a lot of questions about the amount of work done when you change the number of men or number of machines, and I have absolutely never seen anything testing the details of hours per day vs. days worked.

The GMAT is much more apt to ask about two (or more) different machines (or people) working at different rates; the GMAT loves questions of that form --- A works at this rate, B works at that rate, what happens when the work together? etc. See this blog for a further discussion: http://magoosh.com/gmat/2012/gmat-work-rate-problems/

This formula you have, and worrying about the meaning of k, is not going to help you at all on the work questions that are most typical on the GMAT.

Re: Understanding Time & Work formula [#permalink]

Show Tags

02 Apr 2014, 21:17

mikemcgarry wrote:

22990atinesh wrote:

Let M=Men, D=Days, H=Hours, W=Work M ∝ W (M is directly proportional to W) D ∝ W H ∝ W MDH ∝ W MDH = kW MDH/W = k I know MDH represents Total Men hour work and W represents 1 unit of work. Then what does the ratio MDH/W represents.

Dear 22990atinesh, I'm happy to respond.

First of all, I'll suggest that if you put the k on the other side of the equation, it will be much more sensible: kMDH = W So that k = W/(MDH) which would make it vaguely rate-like. Work per man-hour-days, something like that.

I will say, I don't think know this formula is going to help you on the GMAT. You do have to know the basic idea of work rate R, where A = RT (A is the amount of work done). The GMAT tends not to ask a lot of questions about the amount of work done when you change the number of men or number of machines, and I have absolutely never seen anything testing the details of hours per day vs. days worked.

.....

Hello mikemcgarry thanx for your response, I'm not a GMAT Aspirant, I'm just clearing my basic doubts of some aptitude topics.

Re: Understanding Time & Work formula [#permalink]

Show Tags

22 May 2014, 11:58

Dear 22990atinesh

It's good that you are curious to understand the real-world significance of mathematical formulas.

Coming to your ques, \(k = \frac{MDH}{W}\) = \(\frac{Total man-hours worked}{Total units of work done}\) = Man-hours required per unit of work

You can appreciate that this ratio will be useful for some companies. For example, let's say, a car company is debating whether to purchase a few automation machines or not. They may use this ratio in their decision-making. For example, assembling of 1 car may normally take 100 man-hours (that is, k=100), but with the automation machines, it may take only 40 man-hours (that is, k'= 40). This looks like an attractive proposition! Of course, the management will also consider other factors, like costs, in making their decision.
_________________

Please press Kudos if you were helped by my post!

Last edited by JapinderKaur on 22 May 2014, 12:26, edited 1 time in total.

For example, If 6 men working 5 days for 8 hours each can finish a task. How many men would be needed for 4 days for 6 hours each to finish half the task?

Re: Understanding Time & Work formula [#permalink]

Show Tags

23 May 2014, 22:01

MavenQ wrote:

Dear 22990atinesh

It's good that you are curious to understand the real-world significance of mathematical formulas.

Coming to your ques, \(k = \frac{MDH}{W}\) = \(\frac{Total man-hours worked}{Total units of work done}\) = Man-hours required per unit of work

You can appreciate that this ratio will be useful for some companies. For example, let's say, a car company is debating whether to purchase a few automation machines or not. They may use this ratio in their decision-making. For example, assembling of 1 car may normally take 100 man-hours (that is, k=100), but with the automation machines, it may take only 40 man-hours (that is, k'= 40). This looks like an attractive proposition! Of course, the management will also consider other factors, like costs, in making their decision.

Thanx MavenQ, I think I get it .You are trying to say that total Man hour/unit work is constant i.e. MDH/W=k. for example we have given that 2 Men working 3 hours/day works for 4 days to complete a work (unit of work). Calculate how many days required by 1 man working 2 hours/day to complete the 1/2 of that work.

Sol: As we know Man hour/unit work is constant. Hence \(\frac{M_1D_1H_1}{W_1}=\frac{M_2D_2H_2}{W_2}\) Now we can easily plug data in LHS of the above equation. But for RHS as we know, we have to calculate days required by 1 man working 2 hours/day to complete the 1/2 of that work. so we have to double the total Man hour in RHS i.e.

Re: Understanding Time & Work formula [#permalink]

Show Tags

20 Sep 2017, 21:06

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Version 8.1 of the WordPress for Android app is now available, with some great enhancements to publishing: background media uploading. Adding images to a post or page? Now...

Post today is short and sweet for my MBA batchmates! We survived Foundations term, and tomorrow's the start of our Term 1! I'm sharing my pre-MBA notes...

“Keep your head down, and work hard. Don’t attract any attention. You should be grateful to be here.” Why do we keep quiet? Being an immigrant is a constant...