if six men dig a ditch in 21 days,how long would 9 men take?

31.5? is that an option?

14 days

21 days

To find out how long it would take 9 men to dig the same ditch, we can use the concept of man-days. The number of man-days needed to complete a task is equal to the number of people multiplied by the number of days it takes them to finish the job.

In this case, 6 men took 21 days to complete the task. So, the number of man-days for this would be 6 men multiplied by 21 days, which equals 126 man-days.

To determine how long it would take 9 men to complete the same task, we can divide the total man-days required (126) by the number of men (9).

To calculate this, you can use the formula:

Number of days = Total man-days / Number of men

Using our numbers, substituting them into the formula:

Number of days = 126 man-days / 9 men

Simplifying:

Number of days = 14 days

Therefore, 9 men would take 14 days to complete the same task.