please help me! geometry help needed.

Answer: Choice D
181 grams
======================================================
Explanation:
First we need to find the volume of the tennis ball
Since the diameter is d = 6 cm, it divides in half to a radius of r = 3 cm.
[tex]V = \text{volume of a sphere}\\\\V = \frac{4}{3}\pi*r^3\\\\V \approx \frac{4}{3}*3.14*3^3\\\\V \approx 113.04 \ \text{ cm}^3\\\\[/tex]
This leads to
[tex]\text{density} = \frac{\text{mass}}{\text{volume}}\\\\D = \frac{M}{V}\\\\M = D*V\\\\M \approx 1.6*113.04\\\\M \approx 180.864\\\\M \approx 181 \text{ grams}\\\\[/tex]