A sample of gas occupies a volume of 50.0 millilters in a cylinder with a movable piston. The pressure of the sample is 0.00 atmosphere and the temperature is 200 K. What is the volume of the sample at STP?

$\frac{{P}_{1} {V}_{1}}{T} _ 1 = \frac{{P}_{2} {V}_{2}}{T} _ 2$, given a constant quantity of gas.