It takes 12 men 8 hours a day to finish a piece of work in 4 days. In how many days will it take 4 m

For work questions like this, first find the total amount of work in man-hours. Total work = number of men × hours per day × number of days.

Total work = 12 × 8 × 4 = 384 man-hours.

Now the same 384 man-hours must be done by 4 men working 16 hours each day. In one day these men do 4 × 16 = 64 man-hours. So the number of days = 384 ÷ 64 = 6 days.

Check: 4 men × 16 hours × 6 days = 384 man-hours, the same as before. So the work takes 6 days.