$($a$)$ Design a simply supported one$-$way slab for an effective span of $4$m to carry total factored load of $8$ kN$/$m$2.$ Use M$-20$ and Fe$-415$ steel. Check depth as per deflection criteria and check for cracking.

$($b$)$Design a simply supported two$-$way slab of $3\mathrm{.}0$ X $4\mathrm{.}0$ clear span supported on $300$ mm thick walls on four sides. Assume Live load$=5$ kN$/$m$2$ and Floor finish$=1$ kN$/$m$2.$ Take M$-20$ concrete and Fe$-415$ steel. Corners are not held down.