I think a or c but I need to check with someone

What is always true about a positive integer raised to a negative odd power?

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi, r^3 , where r is the sphere’s radius.

Hurry can a triangle can be constructed with angles measuring 115°,55°, and 20°? yes or no