Invance Corp. began the month of April with a cash balance of $21,000. During April the company reported net income of $15,000.

Invance Corp. began the month of April with a cash balance of $21,000. During April the company reported net income of $15,000. The following merchandise sales and purchases and cash receipts and cash payments occurred during April:

Purchased merchandise at a cost of $48,000 on credit

Sold merchandise with a cost of $36,000 on credit for $60,000

Made payments to creditors for merchandise purchases of $56,000

Collected $50,000 from credit customers

What is the balance of the cash account at April 30?

How do you get the answer 15,000?