The volume and pressure of the gas inside the balloon would increase.
Explanation:
The pressure of a gas increases as the temperature also increases, because it promotes a greater agitation of the gas molecules, which when trobar one in the other promote the increase of the pressure. Similarly, this movement also promotes an increase in volume, as it expands the walls of the container that holds the gas.
In the case of the question above, we can see that the balloon is inside the car, which naturally has a high temperature. This temperature is intensified due to the hot summer day.
