$($b$)$ The table below gives the hourly rainfall of three storms that give rise to runoff equivalent of $14,23,$ and $18\mathrm{.}5mm$ respectively. Determine:

$($b$-1)$ the runoff for Storm $1$ using the SCS$-$CN method $($assume $CN=90).(3$ marks$)$

$($b$-2)$ the $-$index for Storms $2$ and $3.$

$(6$ marks$)$

$\backslash$table$[[$Hour$,$Storm $1($mm$),$Storm $2($mm$),$Storm $3($mm$)],[1,2,4,3],[2,6,9,8],[3,7,15,11],[4,10,12,4],[5,5,5,12],[6,4,,3],[7,4,,],[8,2,,]]$