Kerosene $)=(0\mathrm{.}8$ enters through pipe $1$ at $6\frac{m}{s}$ while water enters through section $2$ at $10\frac{m}{s}.$ Assuming complete mixing, calculate:

a$)$ Average velocity through section $3.$

b$)$ The mixture density in section $3.$

Take Diameters of pipes $1,2,$ and $3$ to be $3cm,3cm$ and $4cm.$