I am struggling with the following questions. The questions are attached in the following. I understand the questions is a bit long. However I really hope someone can help. Thanks.

1. Why the ending inventory is $48700?
2. Why the retained earnings is $85940(77,200 + 8,740)? I don't understand where 8740 come from.
3. Why the sales revenue is $137100 (62,100+ 75,000)? I don't understand where 62100 come from.
4. Why the salary expense is $27300 (10,400 + 13,000 + 3,900)? I don't understand where 3900 come from.

BusyBee Company Limited ("BusyBee") is a merchandizing company that specializes in computer accessories.The company uses a periodic inventory system and a first-in-first-out cost flow assumption.Since computer accessory is a very competitive market, BusyBee prepares its financial statements on a monthly basis in order to monitor closely the performance of the company.The trial balance of BusyBee as at 31^stJanuary, 20X2, is as follows:

BusyBee Company Limited

Trial Balance

As at 31^stJanuary 20X2

Cash 61,000

Accounts receivable 50,000

Supplies 5,300

Prepaid rent 35,000

Merchandise inventory 83,400

Equipment 144,000

Accumulated depreciation- equipment 27,000

Accounts payable 62,000

Salaries payable 1,300

Interest payable 1,200

Notes payable 60,000

Share capital- ordinary 150,000

Retained earnings 77,200

The following activities took place in February:

Feb. 1 Received $19,400 keyboards from Mercury Limited, FOB destination, 2/14, n/30.

2 Paid insurance premium of $4,500 for the office equipment. The insurance policy has a term of 6 months effective 1^stFebruary 20X2.

3 Received $24,750 from Pluto Company as full settlement for cordless mice sold on 25^thJanuary 20X2, terms 1/10, n/30.

4 Received a $2,400 credit memorandum from Mercury Limited for the damaged merchandise returned.

8 Billed Haumea Limited for USB flash drives sold of $69,000, terms FOB destination, 2/7, n/40. Sent $600 check for shipping charges.

9 Purchased $18,700 web cameras from Saturn Company, terms 1/8, n/30.

10 Paid $11,700 for two weeks' salary ending 10^thFebruary 20X2, Friday.

11 Purchased supplies $1,200 on credit from Venus Office Supplies Company.

12 Sold $75,000 A-Link routers to Eris company, one-third in cash and the remainder is due on 22^ndMarch 20X2.

15 Paid Mercury Limited in full for the purchase on 1^stFebruary 20X2

17 Granted an allowance of $1,700 to Eris Company as the colour of the cases did not match the specification.

18 Sent a check to Saturn Company for the purchase on 9^thFebruary, in full and $14,200 on account.

24 Paid the bi-weekly salaries of 13,000 and miscellaneous expense of $3,700.

29 Incurred$800 maintenance expense for the office equipment andpaidan electricity bill of $1,600.

Other information available on 29^thFebruary 20X2:

a)Supplies of $3,400 was still available as at 29th February.

b) A physical count of merchandise inventory on 29th February revealed that there was $48,700 of inventory on hand.

c)The note payable in the 31^stJanuary trial balance is an 18-month note dated 1^stNovember 20X1 and carries an 8% interest rate.

d)All the staff worked for the whole month of February.

e)All the equipment was purchased when the company commenced its business and has an estimated useful life of 8 years. The salvage value is 10% of the cost.

f)Rent expired during February is $17,000.