A hall has the dimensions of $10 \mathrm{m}\times 10 \mathrm{m}\times 10 \mathrm{m}$. A fly starting at one corner ends up at the farthest corner. The magnitude of its displacement is,

A body starts from rest and is uniformly accelerated for $30 \mathrm{s}$. The distance travelled in the first $10 \mathrm{s}$ is $x_1$, next $10 \mathrm{s}$ is $x_2$ and the last $10 \mathrm{s}$ is $x_3$. Then $x_1:x_2:x_3$ is the same as