Show all steps pls!

4. Andy had an invoice dated May 25th for $1238.50. The terms of payment were 3/10, n/30. On June 3, Andy made a partial payment of $1000. What amount was credited to Andy's account? (31 days in May) 5. An item costs $30. Operating expenses for the item are estimated at 40% of cost, and the desired operating profit is 20% of selling price. Determine the selling price and markup amount. 6. Student Association sells hot dogs for $2.50 each. The SA buys wieners for $9.60 per pack of twelve, and buns at $2.40 per pack of eight. It costs $80 for condiments for 1000 hotdogs. What is the SA's rate of markup based on the selling price for the hotdogs? 4. Andy had an invoice dated May 25th for $1238.50. The terms of payment were 3/10, n/30. On June 3, Andy made a partial payment of $1000. What amount was credited to Andy's account? (31 days in May) 5. An item costs $30. Operating expenses for the item are estimated at 40% of cost, and the desired operating profit is 20% of selling price. Determine the selling price and markup amount. 6. Student Association sells hot dogs for $2.50 each. The SA buys wieners for $9.60 per pack of twelve, and buns at $2.40 per pack of eight. It costs $80 for condiments for 1000 hotdogs. What is the SA's rate of markup based on the selling price for the hotdogs