Let the required number of bottles be x.
More machines, More bottles (Direct Proportion)
More minutes, More bottles (Direct Proportion)
$\begin{matrix}{\begin{matrix}{Machines} & {6\colon10}\end{matrix}} \\ {\begin{matrix}{Time} & {\, \, \, \, \, \, \, \, \, \, 1\colon4}\end{matrix}}\end{matrix}\Bigr{\}}: : 270:x$
∴$6×1×x=10×4×270$
⇒$x= \frac{(10×4×270)}{6}$
⇒$x=1800$