Please help me solve the following question of basic simple interest... I am having issue solving question 1 part a, b, c & e... I can't figure out where I am making my mistake... Please is the picture below of the question (picture #1) and answer key (picture #2).

to\" W 3 33 onOBLEMS I. The Dixon Sporting Goods purchased 80 life jackets at $20 each, less a 30% trade discount. from Elite Manufacturing Co. on April 5. The terms of the invoice were 2110, U20, n! 30. On April 15, the account- ing department at Dixon sent a check for an amount that gave it credit for one-half the balance due. On April 25. the other half of the invoice was paid. Dixon has a markup of 20% on cost for operating ex- penses and 20% on cost for net prot. During May through July, 50 life jackets were sold at the regular marked prices. In August, the shop marked down the remaining merchandise by 40% for an after-season sale. As one of the assistants in the accounting department for Dixon, your job is to dEtBImille the fOHDWigi a. The total cost of the life jackets before the cash discounts were taken b. The amount remitted on April 15 c. The amount remitted on April 25 d. The total cost and the individual cost per jacket after the cash discounts e. The regular list price of each jacket f, The reduced price of each jacket in August g. The total revenue received from the sale of the 80 life jackets h. The total amount of operating prot or operating loss i, The percent of cost that this prot or loss was [to the nearest tenth) SECTION 3 1. a. $1,120 b. $548.80 c. $554.40 d. $1, 103.20; $13.79 e. $19.31 f. $11.59 g. $1,313.20 h. Operating loss, $10.64 i. 1.0% 3. a. $8,245 b. $8,280; $82.80 c. $115.92 d. $57.96 e. $10,143 f. Operating loss, $207 g. 2.5%