Please help me answer this question, Thank you!

Question

The number of people working on a certain job varies inversely as the time required to do the

job. If 20 men can do a portion of a job in 3 days, how many men can do the same job in 10

days?

Answer 1

Hello Keith,

"The number of people working on a certain job varies inversely as the time required to do the

job."

that means if more people work on that job, the time required to complete that job will decrease.

Mathematically speaking:

(number of ppl working on a job) • (time required to do the job) = constant of variation -----> #1

You're told it takes 3 days for 20 men to do a job, so the constant of variation is 20*3 = 60.

To find how many people would do the same job in 10 days, we still use equation #1:

(number of ppl working on a job) • (10) = 60

Divide both sides by 10, and that will get you the answer.