The time it takes to complete a certain job varies inversely to the number of people working on that job. If it takes 28 hours for 11 carpenters to frame a house, then how long will it take 49 carpenters to do the same job?
A) 40 hr
B) 49 hr
C) 6.3 hr
D) 19.3 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 $T = 28$ hours for $N = 11$ carpenters, we find $k = 28 \times 11$. For $N = 49$ carpenters, $T = k/49 = (28 \times 11)/49 = 6.3$ hours.

The Time It Takes to Complete a Certain Job Varies