A merchant realizes a markup of $42 by selling an item at a markup of 37.5% of cost. The merchant's overhead expenses are 17.5% of the regular selling price. At a promotional sale, the item was reduced in price to $121.66.
a) What is the regular selling price?
b) What is the rate of markup based on the regular selling price?
c) What is the rate of markdown?
d) What is the profit or loss during the promotional sale?