How long would it take six men to complete a job that three men can finish in 40 hours?

To determine how long it would take six men to complete a job that three men can finish in 40 hours, we need to understand the relationship between the number of workers and the time taken to complete a task.

If three men can finish the job in 40 hours, we can calculate the total work in "man-hours." This is done by multiplying the number of men by the hours they work:

3 men x 40 hours = 120 man-hours.

This means the total work required to complete the job is 120 man-hours.

Now, if we have six men working on the same job, we need to determine how long it will take them to do the 120 man-hours of work. Since six men can complete six man-hours of work in one hour, we calculate the time needed like this:

120 man-hours ÷ 6 men = 20 hours.

Therefore, six men would take 20 hours to complete the job. The correct answer highlights the efficient use of manpower and shows how increasing the number of workers can reduce the time required to finish a task.