Accounting questions....using the information, what is the amount of gross profi

[dolnahat]

Purchases $28,000

Purchases discounts $800

Merchandise inventory April 1 $6,500

Merchandise inventory April 30 $7,800

Sales returns and allowances $750

Sales $57,000

Purchases returns and allowances $1,000

Transportation In $880

These are the answer options, and can you please explain why so that I can understand it??? thank you!

What is the amount of gross profit?
31,970
30,470
25,780
56,250
What is the amount of merchandise available for sale?
33,580
30,470
25,780
34,500

[Maabigail]

What is the amount of merchandise available for sale?
Merchandise inventory April 1 $6,500
Purchases $28,000
Purchases discounts ($800)
Purchases returns and allowances ($1,000)
Transportation In $880
Answer: $33,580

What is the amount of gross profit?
Sales $57,000
Sales returns and allowances ($750)
Net sales $56,250
COGS-
Merchandise inventory April 1 $6,500
Purchases $27,080
less Merchandise inventory April 30 ($7,800)
COGS = $25,780
GP = $30,470