Huey's Hip Pizza sells two sizes of square pizzas: a small pizza that measures 6 inches on a side and costs $10, and a large pizza that measures 9 inches on a side and costs $20. If two friends go to Huey's with $30 apiece, how many more square inches of pizza can they buy if they pool their money than if they each purchase pizza alone?
Choose the correct option:  A) 9 square inches  B) 10 square inches  C) 15 square inches  D) 25 square inches  E) 350 square inches

Rationale: "in the first case each can buy one pizza of $ 10 and one pizza of $ 20 . in square inches that would be ( 6 * 6 = 36 ) for the small pizza and ( 9 * 9 = 81 ) for the large pizza . in total sq inches that would be ( 36 + 81 ) * 2 = 234 sq inches . in the second case if they pool their money together they can buy 3 large pizzas . in terms of square inches that would be 3 * 81 = 243 sq inches . hence , the difference is 9 square inches more ( 243 - 234 ) . the correct answer is a"
Answer: A