The asset and liability balances of Stuart Enterprises, as obtained from the comparative balance sheet from its incomplete records are as follows:

	12/31/2019	12/31/2020
Assets
Cash	P3,200	P7,360
Accounts receivable (net)	4,065	8,350
Merchandise inventory (based on physical count)	8,365	6,425
Prepaid expenses	300	400
Equipment (net)	6,000	5,400
Liabilities
Accounts payable	7,365	6,065
Notes payable bank	3,000
Accrued interest on notes payable	150
Accrued operating expenses	250	500

Additional information:

A. The cashbook shows the following:

Receipts
From customers, net of cash discounts of P425	P59,425
From trade creditors for returned goods	110
Disbursements
To trade creditors, net of cash discounts of P560	P43,560
To notes payable and interest	3,300
To customers for returns	115
For expenses	8,400

B. Customers accounts of P425 were written off during 2020. An account of 350, written off in 2019, was recovered in 2020 and recorded among the receipts from customers.

C. Sales returns in 2020 amounted to P385, and purchase returns were P290.

D. An examination of shipping and delivery records disclosed that goods invoiced for P2,500 as of December 31, 2019 and shown as a receivable on that date were actually delivered on January 15, 2020. Of the accounts receivable shown as of December 31, 2020, one for P2,700 (billed amount) was actually delivered on January 7, 2021. Goods received from suppliers on December 30, 2020 amounting to P3,000 were invoiced by the creditor only on January 31, 2021. This amount was not included in the accounts payable as of December 31, 2020.

E. Physical inventory which was taken on December 31, 2020 amounted to P6,425, at cost. Net realizable value of inventory as of that date was P5,800. Inventory shown on December 31, 2019 balance sheet was P8,365, at cost; P8,450 at net realizable value. Inventory is shown on the balance sheet at the lower of cost or net realizable value, and any loss due to inventory write-down is treated as operating expense under asset impairment.

F. Cash discounts are treated as direct reduction from sales and purchases, as the case may be.

G. There was no addition or disposal of equipment during the year.

H. A review of the financial statements of previous years prepared on the basis mentioned in Item E above showed an average gross profit of 30% on net sales. The same markup was maintained in 2020.

Based on the information above, answer the following:

1. How much is the gross sales for the year ended December 31, 2020?
2. How much is the gross purchases for the year ended December 31, 2020?
3. How much is the inventory shortage for the year ended December 31, 2020?
4. How much is the operating expenses other than bad debts and depreciation for the year ended December 31, 2020?
5. How much is the interest expense for the year ended December 31, 2020?
6. How much is the net income before income tax for the year ended December 31, 2020?