He then went to see the oranges being harvested. He found out that the harvest will go on for 2 days. How many sacks do they harvest per day if they harvested a total of 4 sacks of oranges?
1. He went to see the oranges being harvested. 
2. He found out that the harvest will go on for 2 days. 
3. How many sacks do they harvest per day if they harvested a total of 4 sacks of oranges?

We are trying to find out how many sacks of oranges are harvested per day. We are given that the total number of sacks harvested is 4, and that the harvest will go on for 2 days. 

This means that, on average, they harvest 2 sacks of oranges per day.