Q$2.$ A rectangular reinforced concrete beam with dimensions $b=200mm.$ and

$d=500mm.$ to the center of the bars, which are placed all in one row.

If $f_y=275$MPa and $f^{\text{'}}c=30$MPa,

Find the design flexural capacity $\frac{O}{M_n}$ for the following reinforcement:

a$)A_s=5\frac{O}{18}$

b$)A_s=6\frac{O}{30}$

c$)A_s=2\frac{O}{30}+5\frac{O}{36}$

Q$3.$ A reinforced concrete beam with cross$-$sectional dimensions $b=300mm,$

$y=500mm,$ and $a=5m.$ It carries service load of LL Moment $=20kN.m,$

D$.L=5k\frac{N}{m},$ L$.L=7k\frac{N}{m},$ and $P.L=50kN.$

Material strengths are fy $=350$MPa, and $f^{\text{'}}c=31$MPa.

Check whether this beam, if reinforced as below, is adequate to carry this load in

flexure.