Answer
$V_{30^{\circ}}=49.87cm^3$
Work Step by Step
We know that
$\Delta{V}=V\beta\Delta{T}$
Putting the values, we get
$\Delta{V}=50\times(3\times29\times10^{-6})(60-30)=0.13 cm^3$
$V_{30^{\circ}}=V-\Delta{V}=50-0.13=49.87cm^3$
$V_{30^{\circ}}=49.87cm^3$