b$)$ i$)$ A rectangular beam has width of $12$ inch and effective depth of $17\mathrm{.}5$ inch. It is reinfored with $4$ No$-9$ bars in one row. Calculate the noninal moment, Mn and design moment strength, Md$.$ Given: $f^{\text{'}}=4$ksi, $f_y=60$ksi.

$($ii$)$ Show whether the above beam is adequate or not if the beam is to carry a DL$-1\mathrm{.}0$ K$/$tt $($cxcluding self weight$)$ and a concentrated live load, $10$Kip at mid span. The beam is simply supperted with a span of $=20ft.$