Applied Hydraulics #$3\mathrm{.}12\mathrm{.}4.$

In the pipe system depicted in Figure $P3\mathrm{.}12\mathrm{.}4,$ the discharge in pipe $AB$ is $100\frac{m^3}{s}.$ Branch $1$ is $500m$ long, and it has a diameter of $2m$ and a friction factor of $0\mathrm{.}018.$ Branch $2$ has a length of $400m,$ diameter of $3m,$ and a friction factor of $0\mathrm{.}02.$ Determine the length of an equivalent pipe to replace branches $1$ and $2$ assuming the pipe diameter is $3m$ and $f=0\mathrm{.}02.$ Also, determine the flow in branch $1.$