Saylor Enterprises had owner’s equity of $168,000 at the beginning of the period. At the end of the accounting period, the owner’s equity was $198,000.

a. Assuming no additional investment or withdrawals during the period, with expenses of $20,000, what is the amount of revenues for the period?

b. Assuming an additional investment of $13,000 but no withdrawals during the period, with expenses of $20,000, what is the amount of revenues for the period?