a) How far is the center of mass of the Earth-Moon system from the center of Earth? (Mass of Earth is 5.98 × 1024 kg, mass of Moon is 7.36 × 1022 kg , distance between Earth and Moon is 3.82 × 105 km, Earth's radius is 6.37 × 103 km.)
b) What percentage of Earth's radius is that distance?