Solve the problem.
-The time it takes to complete a certain job varies inversely to the number of people working on that job. If it takes 36 hours for 7 carpenters to frame a house, then how long will it take 54 carpenters
To do the same job?
A) 40 hr
B) 10.5 hr
C) 4.7 hr
D) 54 hr

Question

Quizplus · Accepted Answer

The time it takes to complete a job varies inversely with the number of people, so $T = k/N$, where $T$ is time, $N$ is the number of people, and $k$ is a constant. Given $T = 36$ hours for $N = 7$ carpenters, we find $k = 36*7 = 252$. For $N = 54$ carpenters, $T = 252 / 54 = 4.7$ hours.

Solve the Problem. -The Time It Takes to Complete a Certain Job Varies