Situation $7$: A rectangular channel $6m$ wide and $2m$ deep has a slope of $1$ in $1100$ and is lined with good rubble masonry $(n=0\mathrm{.}017).$ It is desired to increased the channel slope with a favorable section. The dimension of the section maybe changed but the channel must contain the same amount of lining as the old. Using kutter's formula:

$23.$ Compute the value of kutter's coefficient $"C"$ of the old channel

$24.$ Compute the depth of new section

$25.$ Compute the probable increase in discharge