Bunuel
Huey's Hip Pizza sells two sizes of square pizzas: a small pizza that measures 10 inches on a side and costs $10, and a large pizza that measures 15 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?
A. 5 square inches
B. 10 square inches
C. 15 square inches
D. 25 square inches
E. 350 square inches
Notice it’s a better deal to buy the 15-inch square pizza than the 10-inch square pizza since spending $20 on a 15^2 = 225 in^2 pizza is better than $10 on a 10^2 = 100 in^2 pizza (notice that 225/20 > 100/10).
Thus, when they pool their money, with $60, they should buy three $20 pizzas.
If they were to not pool their money and buy the pizzas separately, each should buy one $20 pizza and one $10 pizza. Thus in total, they should buy two $20 pizzas and two $10 pizzas.
Thus, it’s three $20 pizzas versus two $20 pizzas and two $10 pizzas. However, if we take away the two $20 pizzas from both sides, it’s one $20 pizza against two $10 pizzas.
Since one $20 pizza is 225 in^2 and two $10 pizzas are 2 x 100 = 200 in^2, pooling the money together buys 225 - 200 = 25 in^2 of extra pizza.
Answer: D