If 5 men working 6 hours a day can reap a field in 20 days, in how many days will 15 men reap the field if they work for 8 hours a day?

1 Answer
May 22, 2018

Answer:

#5# days

Explanation:

Instead of working with a number of men and the number of hours in a day, consider the number of 'man-hours' used.

#5# men working for #6# hours a day means:
#5 xx6 = 30# man-hours a day.

The entire task of reaping the field takes:
#30 xx 20 = 600# man-hours

The question involves inverse proportion because if there are more men working and they work for more hours each day, then the task will be completed in fewer days.

#15# men working for #8# hours a day means:
#15 xx 8 = 120# man-hours per day

To complete the task which requires #600# man-hours:

#600 div 120 = 5 # days