He then went to see the oranges being harvested. He found out that they harvest 8 sacks per day. How many days will it take to harvest 24 sacks of oranges?
. 

The first day, they harvest 8 sacks. 
The second day, they harvest 8 more sacks. 
The third day, they harvest 8 more sacks. 

This continues until they have 24 sacks, which will be on the third day.