Dunk Manufacturing Company’s CFO is reviewing its Sales planning for the next 3 months, which shows Sales at $60k in October and growing by $10k each of the following 2 months. Historically, half of Dunk’s sales are made on credit terms and the half cashed in immediately. Half of the credit sales are historically paid at 30 days and the other half at 60 days. 

Calculate the amount of Cash that received from clients in December .