From Newtons law of gravitation we know that the force of gravity between two bodies Fg is Fg=(G*M*m)/r², where G is the gravitational constant, G=6.67*10^-11 m³/(kg s²), M and m are masses and r is the distance between those masses. So to get the distance we need to solve for r:
r²=(G*M*m)/Fg
and when we take the square root:
f=√{(G*M*m)/Fg}.
We input the numbers and get: r=19603832.5 m or in scientific notation:
r=1.96*10^7 m. So the correct answer is the first one: 2*10^7 m.
