What is the volume of a sphere that has a 10 m diameter

This is so hard and it’s for a test

Lena reflected this figure across the x-axis. she writes the vertices of the image as a'(−2, 8), b'(−5, 6), c'(−8, 8), d'(−4, 2).

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way