A weather balloon is filled with helium that occupies a volume of 5.75 104 L at 0.995 atm and 32.0°C. After it is released, it rises to a location where the pressure is 0.720 atm and the temperature is -14.7°C. What is the volume of the balloon at that new location?

Answer 1

the volume is directly proportional to the absolute (Kelvin) temperature
... and inversely proportional to the ambient pressure