How to calculate the light-years and convert to miles

Question description

1. If a galaxy is 1,000 Mpc away, how fast is it receding
from us?

2. The Milky Way has a radius of approximately 100,000
light years. How many miles is
that? How long would it take you to
travel across our galaxy if you were traveling at 50% the speed of light
(be sure to show your work for full credit)?