5) Sandblast Company has a predicted operating income of $84,000. Their total variable expenses are $24,000 and their total fixed expenses are $30,000. They have a unit contribution margin of $10.

a. Calculate the required sales in units to achieve the predicted operating income.

b. Calculate the required sales in units to achieve the predicted operating income if the company's fixed expenses double from $30,000 to $60,000.