Compute bad debt expense based on the following information:

(a) RLF Company estimates that 2% of net credit sales will become uncollectible. Sales revenue are $600,000, sales returns and allowances are $30,000, and the allowance for doubtful accounts has a $6,000 credit balance.

(b) RLF Company estimates that 10% of accounts receivable will become uncollectible. Accounts receivable are $100,000 at the end of the year, and the allowance for doubtful accounts has a $500 debit balance.