What is the inner surface area of a spherical shell of inner radius 15 cm and outer radius 16 cm? (correct up to 2 decimal places)

A) 706.86 cm²
B) 804.25 cm²
C) 2827.43 cm²
D) 3216.99 cm²

To calculate the inner surface area of the spherical shell, we only need to focus on the inner radius.

The formula for the surface area \( A \) of a sphere is:

\[ A = 4\pi r^2 \]

Where \( r \) is the radius of the sphere.

For the given problem:
- The inner radius \( r = 15 \) cm

Using the formula for surface area:

\[ A = 4 \times \pi \times (15)^2 \]

\[ A = 4 \times \pi \times 225 \]

\[ A = 900\pi \]

Now, using the approximate value of \( \pi \approx 3.1416 \):

\[ A \approx 900 \times 3.1416 \]

\[ A \approx 2827.43 \, \text{cm}^2 \]

Thus, the inner surface area of the spherical shell is approximately **2827.43 cm²**.

The correct answer is:

**C) 2827.43 cm²**