RECORDING SALES Sullivan Company sells industrial cleaning supplies and equipment to other businesses.

During the first quarter of 2009, the following transactions occurred:

a. On January 10, Sullivan sold on credit 50 cases of paper towels to the WMT Manufacturing Company at a list price of $800 for the entire lot of 50 cases.

b. On January 14, West Side Mall Corporation purchased on credit from Sullivan two floor polishers at a list price of $150 each and 10 cases of nonskid wax at a list price of $50 per case.

c. On January 16, West Side Mall returned to Sullivan four cases of the wax purchased on January 14.

d. On January 24, WMT paid Sullivan for its purchase of January 10.

e. Tom’s Cleaning Service purchased on credit from Sullivan three cases of carpet shampoo at a list price of $64 per case on January 31.

f. On February 3, West Side Mall paid Sullivan for its purchase less the wax returned on January 16.

g. Tom’s Cleaning Service paid Sullivan for its purchase of January 31 on February 10.

h. WMT returned to Sullivan a case of oversize paper towels on February