A company that records credit purchases in a Purchases Journal and records purchase returns in its General Journal made the following errors. List each error by letter and, opposite each letter, tell when the error should be discovered:
a. Made an addition error in determining the balance of a creditor's account.
b. Made an addition error in totaling the Office Supplies column of the Purchases Journal.
c. Posted a purchase return to the Accounts Payable account and to the creditor's account but did not post to the Merchandise Inventory account.
d. Posted a purchase return to the Merchandise Inventory account and to the Accounts Payable account but did not post to the creditor's account.
e. Correctly recorded a $4,000 purchase in the Purchases Journal but posted it to the creditor's account as a $400 purchase.