He then went to see the oranges being harvested. He found out that they harvested 54 sacks of oranges. How many days did it take to harvest them if they harvested 18 sacks of oranges per day?
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We know that 18 sacks of oranges were harvested per day. 

We also know that 54 sacks of oranges were harvested in total. 

We want to know how many days it took to harvest the oranges. 

To solve this problem, we can divide 54 by 18. 

54 divided by 18 equals 3. 

It took 3 days to harvest the oranges.