I am having so much trouble figuring out these types of questions, any help would be greatly apreciated.

Use this inventory information for the month of September to answer the following question.

Sept 1 Beginning inventory 10 units @$120
5 Purchase 60 units @$112
14 Sale 40 units
21 Purchase 30 units @$116
30 Sale 28 units

Assuming that a perpetual inventory system is used, what is ending inventory on a FIFO basis?
a) $3,704
b) $7,696
c) More information is needed
d) $3,664

Well Easy First In First Out First You Have 10 Units For 120 That Mean You Have A Balance Of 1200 Now You Have A Nother Units 60 For 112 Now Sell The Ten Units Costing 120 And 30 Costing 112 Then You Have Left 30 Units Costing 112 Then Purchase 30 Units For 116 Now Subtract 28 Units Costing 112 And Your Left With 2 Units Costing 112 And 30 Costing 116 Final Answer 2x112 Plus 30x 116 Euals 3704

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