Answer:
See explanation
Step-by-step explanation:
When a helium blimp rises in the atmosphere, a point eventually comes when the buoyancy of the blimp compared to the air it displaces is no longer greater than gravity's pull on the blimp hence it stops rising.
A smaller blimp will rise more than a larger blimp at the same pressure because the weight of the blimp determines the altitude to which it will rise.