Two mountains are 1.00 km apart. If their masses are identical (2.00 × 1010 kg), what is the force due to gravity between the mountains?

Question

Fg=(GMm)/ r^2
=(6.67x10^-11 N*m^2/kg^2)(1010kg) (1010kg)/ (1000m)^2
=6.80x10^-11 N

But the possible answers are:
2.67x 10^4 N
1.33x 10^-6 N
2.67x 10^7 N
2.67x 10^10 N

Can someone tell me what I'm doing wrong? Thanks

Answer 1

M=m=2.00 × 10^10 kg

Answer 2

2.67x10⁴