If a balloon containing 3000 L of gas at 39C and 99 kPa rises to an altitude where the pressure is 45.5 kPa and the temperature is 16C, the volume of the balloon under these new conditions would be calculated using the following conversion factor ratios

Answer 1

Remember P1V1 = P2V2 and V1/T1 = V2/T2.
Solve the first equation for V2 = P1V1/P2 and that is the same as V2 = V1 x P1/P2. So P1/P2 is the pressure ratio (factor) you want. Do the same kind of thing for T.

Answer 2

234