so if you get 20% of 13,668 you get 820.08
If you get 20% of 13,666 you get 819.96
If you get 20% of 13,667 you get 820.02
and if you get 20% of 13,665 you get 819.90
so if they want you to round the cents then 13,666 would be your answer because when you do this ----> 13,666X.06=819.96 you might have to round the 6 to 9 which makes 819.96 into 820 so answer is B