This formula Is for gravitational force and r represent distance between two bodies ,example- earth and you when you jump there will a distance but you will be attracted by the earth. If you change planet the number used in the formula will change and so Will gravity. (GM=Mass of body ) (g=costant)
To answer the specific problem, the balloon contains 480kg
of helium. I am hoping that this answer has satisfied your query and it will be
able to help you, and if you would like, feel free to ask another question.