If a large pizza cost 15 dollars and the medium pizza is 9 dollars.Since the pizza parlor sold only 5 large pizzas, then… 15 x 5 = 75Deduct this from the total amount of pizza sold…$291 - $75 = $216So, the pizza parlor sold a total of $216 for the medium pizzas. Divide this to the amount of one medium pizza. $216 / 9 = 24.So the pizza parlor sold a total of 24 medium pizzas.