A retailer buys items for $55. At an original retail price of $85 it expects to sell 1,000 units.
A If the price is marked down to $75 how many units must the retailer sell to earn the same total gross profit it would attain with an $85 price?
B If the price is marked up to $90 how many units must the retailer sell to earn the same total gross profit it would attain with an $85 price?