Gravitational force Fg = \(\frac{Gm_1m_2}{r^2}\) = 6.67N

\(m_1\) = 10\(^{24}\)kg,  \(m_2\) = 10\(^{27}\)kg, G =  6.6 x 10\(^{-11}\)Nm\(^2\)kg\(^{-2}\) and r = ? 

6.67 = \(\frac{ 6.6\times 10^{-11}\times10^{24}\times10^{27}}{r^2}\)

6.67r\(^2\) =  6.6 x 10\(^{40}\)

r\(^2\) = \(\frac{6.6\times10^{40}}{6.67}\) \(\approx\) 9.89 × 10\(^{39}\)

r = \(\sqrt{ 9.89\times10^{39}}\)  \(\approxeq\) 9.94 × 10\(^{19}\)m  → 1.0 x 10\(^{20}\)m