.
At the pencil factory, the assembly line produces 225 pencils in a batch.
The pencils are packaged in BOXES with 20 each.
If 3 batches are made in one day, how many pencils will be leftover at the end.
~~~~~~~~~~~~~~~~
The total pencils made is 225*3 = 675.
Divide it by 20 with the remainder.
675 = 33*20 + 15.
The remainder 15 is the answer to the problem's question.
Solved and explained.