#$1.$ A development is shown in the figure below. The commercial area will be $50\%$ asphalt, $50\%$ concrete$/$roof$.$ The city park will have a slope of $1\%$ and be maintained in good condition. To simplify this problem, the time of concentrations for each area are also shown in the figure.

$($a$)$ Using the Rational Method, what is the design flow at the inlet for a $10-$year design storm? Hint: consider the two different scenarios $($just commercial area with shorter tc$,$ and total area with longer tc$)$ and pick the worst case.

$($b$)$ What size storm pipe should be specified downstream of this inlet for the $10$ year design storm? Assume the pipe will be concrete $)=(0\mathrm{.}015$ and laid on a $1\mathrm{.}0\%$ slope.