9/1 beg. inv. gross unit: 200 price: $25

9/7 purchase gross unit: 450 price: $28 purchase: $12,600 purchase discount: $212.80 purchase returns: $1,960 freight in: $125

9/13 sold 550 units 9/20 purchase gross units: 780 price:$31 purchases: $24180 discounts: $688.20 returns: $3100 freight in: $296

9/28 sold 600 units

9/30 purchase units: 250 price:$34 purchases: $8500 discounts: $255 returns: $0 freight in: $100

ending inv. 100 units

1. what is % discount on 9/30 2. freight charge per unit 9/30 and 9/20