[Rula]

Can you Tell me how we found the balance in perpetual questions??
for example Like this one but I can't Understand it
aEx. 176
Romano Company uses the perpetual inventory system and had the following purchases and
sales during March.
Purchases Sales
Units Unit Cost Units Selling Price/Unit
3/1 Beginning inventory 100 $40
3/3 Purchase 60 $50
3/4 Sales 70 $80
3/10 Purchase 200 $55
3/16 Sales 80 $90
3/19 Purchase 40 $60
3/25 Sales 120 $90
Instructions
Using the inventoryand sales data above, calculate the value assigned to cost of goods sold in
March and to the ending inventory at March 31 using (a) FIFO and (b) LIFO.

aSolution 176 (20 min.)
a) FIFO
Date Purchases Sales Balance
3/1 (100 @ $40) $4,000
3/3 (60 @ $50) $3,000 (100 @ $40)
(60 @ $50) $7,000
3/4 (70 @ $40) $2,800 (30 @ $40)
(60 @ $50) $4,200
3/10 (200 @ $55) $11,000 (30 @ $40)
(60 @ $50)
(200 @ $55) $15,200
3/16 (30 @ $40) (10 @ $50)
(50 @ $50) $3,700 (200 @ $55) $11,500
3/19 (40 @ $60) $2,400 (10 @ $50)
(200 @ $55)
(40 @ $60) $13,900
3/25 (10 @ $50) (90 @ $55)
(110 @ $55) $6,550 (40 @ $60) $7,350
March cost of goods sold = $13,050 ($2,800 + $3,700 + $6,550)
March 31 inventory = $7,350



How we found the balance.. why those numbers? I need more details to understand :(