Answer:
300 divided by 6
Explanation:
Given that;
Number of crates of apple owned by fruit seller = 3 crates
Number of apples in each crate = 100 apples
He packed 6 apples in 1 box;
Unknown:
Number of boxes needed to pack all the apples = ?
This problem is pretty straight forward;
Number boxes needed to pack all apples =

Input the parameters and solve;
Number of boxes need to pack all apples =
=

So the solution is 300 divided by 6