Final answer:
The helium in the tank must have a greater volume than the helium in one balloon in order to fill all 50 balloons. The pressure inside the tank should also be greater than the pressure inside the balloons to allow the helium to flow.
Step-by-step explanation:
The helium in the small tank must have enough volume to fill 50 balloons. Since a relatively small amount of additional helium is added to each balloon, the volume of helium in the tank should be greater than the volume of helium in one balloon. Otherwise, it would not be possible to fill all the balloons. Additionally, the pressure inside the tank should be greater than the pressure inside the balloons in order to allow the helium to flow from the tank into the balloons.