The Earth Has Mass 5 $\times$ 10²⁴ Kg $\times$ 10²² Kg and Is 3

Multiple Choice

The Earth has mass 5.89 $\times$ 10²⁴ kg.The moon has mass 7.36 $\times$ 10²² kg and is 3.84 $\times$ 10⁵ km from Earth.How far from the center of Earth is the center of mass of the Earth-moon system?

A) 4.7 $\times$ 10³ km
B) 7.4 $\times$ 10³ km
C) 1.9 $\times$ 10⁵ km
D) 2.1 $\times$ 10⁵ km
E) 3.8 $\times$ 10³ km