Set up systems of equations and solve by any appropriate method. All numbers are accurate to at least two significant digits.

A person engaged a workman for 48 days. For each day that he labored, he received 24 cents, and for each day he was idle, he paid 12 cents for his board. At the end of the 48 days, the account was settled, when the laborer received 504 cents. Determine the number of working days and the number of days he was idle.