(iii) (3x – 7): (4x + 3) is the sub-triplicate ratio of 8: 27
And the sub-triplicate ratio of
\[\begin{array}{*{35}{l}}
8:\text{ }27\text{ }=\text{ }2:\text{ }3 \\
\left( 3x\text{ }-\text{ }7 \right)/\text{ }\left( 4x\text{ }+\text{ }3 \right)\text{ }=\text{ }2/3 \\
9x\text{ }-\text{ }8x\text{ }=\text{ }6\text{ }+\text{ }21 \\
x\text{ }=\text{ }27 \\
\end{array}\]