SOLUTION: This problem was on a pre-employment exam. If 6 men can do a piece of work in 14 days, how many men are needed to do the work in 21 days?

Algebra ->  Human-and-algebraic-language -> SOLUTION: This problem was on a pre-employment exam. If 6 men can do a piece of work in 14 days, how many men are needed to do the work in 21 days?      Log On


   

Question 99755: This problem was on a pre-employment exam.
If 6 men can do a piece of work in 14 days, how many men are needed to do the work in 21 days?
Found 2 solutions by Earlsdon, ankor@dixie-net.com:
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Try this!
6 men in 14 days = x men in 21 days. Written as a proportion:
6%2F14+=+x%2F21 Multiply both sides by 21.
6%2821%29%2F14+=+x Simplify.
6%283%29%2F2+=+x
x+=+9
It'll take 9 men to do the same job in 21 days.
//////////////////////////////////////////////
My answer here is incorrect!
Please see the correct answer (#72623) of 4 men given by ankor.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
This problem was on a pre-employment exam.
If 6 men can do a piece of work in 14 days, how many men are needed to do the work in 21 days?
:
It helps to convert the completed job to man-days
:
In this job, 6 * 14 = 84 man-days required to complete the job
:
If you want the job done 21 days: 84%2F21 = 4 men will complete it in 21 days