can someone help me with this problem ( I'm quite new with some terms)

A satellite is to be placed in an elliptical orbit, with the center of the earth as one focus. The satellite's maximum distance from the surface of the earth is to be 22380 km , and its minimum distance is to be 6540 km . Assume that the radius of the earth is 6400 km , and find the eccentricity of the satellite's orbit.

Thanks in advance!