SOLUTION: Hi it takes 15 days for 10 workers working 8 hours a day to finish an order. How many workers working 4 hours a day would be needed to finish the order in 10 days. thanks

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: Hi it takes 15 days for 10 workers working 8 hours a day to finish an order. How many workers working 4 hours a day would be needed to finish the order in 10 days. thanks      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1131997: Hi
it takes 15 days for 10 workers working 8 hours a day to finish an order. How many workers working 4 hours a day would be needed to finish the order in 10 days.
thanks
Found 4 solutions by joshuajz, josgarithmetic, ikleyn, greenestamps:
Answer by joshuajz(12) About Me  (Show Source):
You can put this solution on YOUR website!
15 people w/ 80 hours of work being done a day. That's a total 1200 hours to complete the project. 1200/10 = 120 hours needed a day. 120/4 = 30 workers.
Therefore 30 workers are needed.

Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
10r%2A15%2A8=1--------------15 days at 10 hours per day is 120 hours.


n%2Ar%2A10%2A4=1-------------n workers, for 10 days at 4 hours per day, same ONE ORDER


10r%2A120=n%2Ar%2A40
nr%2A40=1200r
n=1200%2F40
highlight%28n=30%29

Answer by ikleyn(52802) About Me  (Show Source):
You can put this solution on YOUR website!
.
Use the proportion

1%2F%2815%2A10%2A8%29 = 1%2F%2810%2Ax%2A4%29,


where x is the unknown number of workers under the question.


The proportion says that the rate of work of each single worker is the same, measured in parts of the total job per hour per worker.


From the proportion,  find  x = %2815%2A10%2A8%29%2F%2810%2A4%29 = %2815%2A8%29%2F4 = 15*2 = 30 workers.     ANSWER


By doing in this way, you have easy way to create an equation (a proportion) based on clear idea of the rate of work.


So, you will never make a mistake in this way.

-----------------

To see many other similar solved problems,  look into the lesson
    - Rate of work problems
in this site.


Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


You already have three responses showing very different ways of solving problems like this. All are very good methods; different students will have preferences for different methods. Find a way that "works" for you.

Here is the method I use because it "works" best for me.

Compare each of the new parameters to the given parameters and see how it changes the number of workers required:
(1) 4 hours a day instead of 8: keeping the number of days the same, half as much time each day means 2 times as many workers. 10*2 = 20.
(2) 10 days instead of 15 days: keeping the number of hours per day the same, 2/3 as many days means 3/2 as many workers. 20*3/2 = 30.

Answer: You need 30 workers to do the same job in 10 days working 4 hours a day.