Gerbig, Inc., collects cash from customers in advance and from other customers after the sale. Journalize the following transactions for Gerbig:
a. Accrued revenue. Some customers pay Gerbig after Gerbig has performed service for the customer. During 2016, Gerbig performed services for $22,000 on account and later received cash of $7,000 on account from these customers.
b. Unearned revenue. A few customers pay Gerbig in advance, and Gerbig later performs the service for the customer. During 2016, Gerbig collected $5,500 cash in advance and later earned $4,000 of this amount.