On September 1 College Office Supply had an inventory of 30 deluxe pocket calculators at a cost of $20 each. The company uses a perpetual inventory system. During September these transactions occurred:

Sept. 6 Purchased 80 calculators at $19 each from Digital Co. for cash.

9 Paid freight of $80 on calculators purchased from Digital Co.

10 Returned two calculators to Digital Co. for $40 credit (including refund of freight cost) because they did not meet specifications.

12 Sold 26 calculators costing $20 (including freight) for $30 each to Campus Book Store, terms n/30.

14 Granted credit of $30 to Campus Book Store for the return of one calculator that was not ordered.

20 Sold 30 calculators costing $20 for $30 each to Varsity Card Shop, terms n/30.