Diane and Darryl both work in sales. Diane gets paid a base salary of $200 per week and $10 per hour. Darryl gets paid a base salary of $250.
a) How much does Diane earn if she works 20 hours in one week?

b) If Darryl earns the same total (your answer in part a) in 20 hours, how much does he earn per hour?