solve the three parts please

Purchase-Related Transactions The Stationery Company purchased merchandise on account from a supplier for $11,900, terms 1/10, n/30. The Stationery Company returned merchandise with an invoice amount of $1,400 and received full credit. a. If The Stationery Company pays the invoice within the discount period, what is the amount of cash required for the payment? b. Under a perpetual inventory system, what account is credited by The Stationery Company to record the return? Normal Balances of Accounts for Retail Business What is the normal balance of the following accounts? a. Cost of Goods Sold b. Customer Refunds Payable c. Delivery Expense d. Estimated Returns Inventory e. Inventory f. Sales g. Sales Tax Payable Journalize the entries to record the following selected transactions. a. Sold $390,000 of merchandise on account, subject to a sales tax of 6%. The cost of the goods sold was $230,100. If an amount box does not require an entry, leave it blank. b. Paid $45,810 to the state sales tax department for taxes collected, If an amount box does not require an entry, leave it blank