Cost: 6000+1500+2600+3000 =13100.

Profit: 29800-13100 =16700.

Accrual basis: income: 5000+8000+18000 = 31000.

Cost: 6000+1500+5800+2600+1000+3000 =19900.

Profit: 31000-19900 =1100.

Reason: Cash receipts and payments under the cash basis, regardless of whether the economic business associated with the cash receipt and payment bank actually occurs, are recorded as income and expenses in the period in which they occur. Accrual basis is characterized by the occurrence of the right to receive cash or the responsibility to pay cash, and confirms the income and expenses, creditor's rights and debts of the current period.