Problem $1,$ Pipe $1,2,3,$ and $4$ have lengths of $300$m$,240$m$,210$m$,$ and $450$m$,$ all being new castion. Pipe $2$ and $3$ are laid in parallel both drawing from $1$ and discharging into $4.$ If $1,$ zand $4$ have diameters of$200$mm$,150$mm$,$ and $250$mm respectivaly,