Answer
25.5 L
Work Step by Step
At a given temperature and pressure,
$V\propto n$
Or $V\propto mass$
So if 50.75 g occupies 10.0 L at STP,
1 g occupies $\frac{10.0\,L}{50.75}=0.197\,L$
129.3 g occupies $0.197\,L/g\times129.3 g$
$=25.5\,L$