Find the sub-triplicate ratio of $1:216$.

Find the sub-triplicate ratio of $\frac{1}{8}:\frac{1}{125}$.

Find the sub-triplicate ratio of $27a^3:64b^3$.

Arrange the following ratios in ascending order of magnitude:

$2: 3,17: 21,11: 14$ and $5: 7$