To determine what happens to the volume of the gas in the balloon when the temperature and pressure change, we can use the Combined Gas Law. The Combined Gas Law relates pressure, volume, and temperature of a gas and is expressed as:
\[ \frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2} \]
Where:
- \(P_1\) and \(V_1\) are the initial pressure and volume,
- \(T_1\) is the initial temperature in Kelvin,
- \(P_2\) and \(V_2\) are the final pressure and volume,
- \(T_2\) is the final temperature in Kelvin.
Since you are changing both the temperature and pressure, the Combined Gas Law is the most appropriate choice for this scenario.