Q$3.$ Given: assuming that $f_c^{\text{'}}=4500$ psi, Grade $75$ rebars and $b=18$ in$.$ and $h=36$

in$.,$ as shown in Fig. $3.$ The beam has a simple support boundary and is designed to

carry a service dead load of $200l\frac{b}{f}t($including self weight$)$ and a service live

load of $1800l\frac{b}{f}t.$

Determine: a$)$ Maximum moment due to applied loads

b$)$ Reinforcement area $($select size of bars and number$)$

c$)$ Re$-$check the flexural capacity

d$)$ Sketch the final design cross section

Fig. $3$