Real Pizza is offering a student sale on its world-famous pizza! For the same price of $12.99, you can choose either option A or option B (see below).

2 Medium Pizzas (12" diameter). Each medium pizza has 6 slices.
1 Large Pizza (18" diameter). Each large pizza has 12 slices.

Which pizza offer is the best deal? Use what you know about circles to select an answer. Computational work must be shown to receive full credit.

(6 points)

1 answer

To determine which pizza option offers a better deal, we need to compare the area of the pizzas in each option since the price is the same for both offers.

1. Calculate the area of the pizzas:

The area \( A \) of a circle is calculated with the formula: \[ A = \pi r^2 \] where \( r \) is the radius of the circle.

Option A: 2 Medium Pizzas (12" diameter)

  • Radius of one medium pizza: \[ r = \frac{12}{2} = 6 \text{ inches} \]

  • Area of one medium pizza: \[ A_{medium} = \pi (6^2) = \pi \times 36 = 36\pi \text{ square inches} \]

  • Total area for 2 medium pizzas: \[ A_{total_medium} = 2 \times 36\pi = 72\pi \text{ square inches} \]

Option B: 1 Large Pizza (18" diameter)

  • Radius of the large pizza: \[ r = \frac{18}{2} = 9 \text{ inches} \]

  • Area of the large pizza: \[ A_{large} = \pi (9^2) = \pi \times 81 = 81\pi \text{ square inches} \]

2. Compare the total areas:

  • Area of 2 medium pizzas (Option A): \( 72\pi \)
  • Area of 1 large pizza (Option B): \( 81\pi \)

3. Conclusion:

To determine which option provides more pizza:

  • Area of Option A: \( 72\pi \approx 226.08 \text{ square inches} \) (using \( \pi \approx 3.14 \))
  • Area of Option B: \( 81\pi \approx 254.47 \text{ square inches} \)

Since \( 81\pi > 72\pi \), Option B (1 Large Pizza) provides a better deal as it has more pizza area for the same price.

Final Answer:

Option B (1 Large Pizza) is the better deal.