The gravitational force between two objects is 2000 N. The mass of each probe is reduced to one third of its original mass. How much the distance between two objects change to keep the gravitational force between them 2000 N?

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles