The 10-Cent Store on February 1, 2021 purchased $21,540 of merchandise from Holiday Express under the terms 1/8, n/20. On February 3, 2021 10-Cent returned $940 of merchandise because the items were broken. On February 10, 2021, Holiday Express gave 10-Cent a $1,040 allowance because the some of the merchandise was the wrong color and would be harder to sell.

Required: (a) If 10-Cent Store pays Holiday Express the entire amount it owes on February 8, 2021, how much will it pay to Holiday Express?

(b) If 10-Cent Store pays Holiday Express the entire amount it owes on February 28, 2021, how much will it pay to Holiday Express?

Please show the detailed steps for each problem and each step and each number where come from. I don't know how to solve this problems. Thank you so much!!!

In addition:

I don't understand why question A answer is.

(21540 - 940 -1040) * 99% =19364.4

Becasue 1/8, n/20, and on February 10 is 1040, but question is asking for February 8.

Can I calculate like: (21540-940) *99%