Please answer problem $2$ in details

Urgent!

Problem# $1$

A storm sewer system for a watershed consists of four areas A$,$ B$,$ C and D as given in Figure $1.$ The direction of flow from each area and between the manholes is given by an arrow: Using rational method, determine the $25-$year peak flow for each sewer section. The IDF given in Figure $2($Page $2)$ reflects the intensityduration$-$frequency relationships for the watershed. Assume the time travel between each manhole is $5$ minutes.

Figure $1$

Table $1$

$\backslash$table$[[$Drainage Area,Arae $($acres$),$Coefficient of runoff, C$,$Overland flow time $($minutes$)],[$A$,5,0\mathrm{.}6,8\mathrm{.}0],[$B$,5\mathrm{.}4,0\mathrm{.}7,9\mathrm{.}2],[$C$,2\mathrm{.}5,0\mathrm{.}7,7],[$D$,6\mathrm{.}5,0\mathrm{.}5,14\mathrm{.}5]]$

Problem # $2$

For the same layout shown in Problem #$1$ above, recalculate the design flow for each sewer section by determining the overland flow using any suitable method if the information provided Table $2$ are applicable. The average velocity through each sewer pipe $=4f\frac{t}{sec}$ and the rainfall intensity $($in$/$hr$)$ is represented by an IDF relationship $i=\frac{100}{t_c+15}$;$t_c$ in minutes.

Table $2$

$\backslash$table$[[$Drainage Area,Path length,Path Slope$],[$A$,500,0\mathrm{.}008],[$B$,1500,0\mathrm{.}01],[$C$,600,0\mathrm{.}0075],[$D$,750,0\mathrm{.}01]]$

Page $2$ of $2$

Prof. Nuhu Dalhat Mu'azu

Figure $2$: Intensity$-$duration$-$frequency $($IDF$)$ curve for Problem#$1$

Please i need the answer of problem$2$