SOLUTION: The number of workers is required to complete a job varies inversely as the time spent working. It takes 4 hours for 20 workers to raise a barn. How long would it take 25 people to

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The number of workers is required to complete a job varies inversely as the time spent working. It takes 4 hours for 20 workers to raise a barn. How long would it take 25 people to      Log On


   

Question 879900: The number of workers is required to complete a job varies inversely as the time spent working. It takes 4 hours for 20 workers to raise a barn. How long would it take 25 people to raise a barn? (In order to receive credit you must use a system of equations.)
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
Unsure if you want this as a inverse variation problem or as a uniform rates problem.
As written, n for count of workers, t for time in hours,
n=k%2Ft is the translation of the first sentence.

Second sentence, first part, after solving the formula for k,
k=n%2At
k=20%2A4
k=80

The variation formula can now be more specifically given as n=80%2Ft.

Third sentence, n=25, t is unknown. Find t.
25=80%2Ft
1%2F25=t%2F80
t=80%2F25
t=16%2F5
t=3%261%2F5 hours