Darnelle works for a real estate agent. She receives a basic wage of $250 per week plus commission on sales. The rate of commission is variable. For houses up to $300,000 the commission is 0.5%. For houses over $300,000, the commission is an additional 0.25% on the amount over $300 000. How much pay did she receive in the week she sold a house for
a. $280 000
b. $428 000
