$1.)$ In the slab system whose material is $C\frac{30}{S}420,$ beam widths $(b_w),$ the thickness and the unit weight of the plaster, leveling concrete and floor covering and also the live loads acted on each slab are given below. According to this

Beam width $(b_w)$:$25cm$

The thickness $(h_f)$ and unit weight $()$ of the plaster: $2c\frac{m}{20}k\frac{N}{m^3}$

The thickness $(h_f)$ and unit weight $()$ of the floor covering: $4c\frac{m}{22}k\frac{N}{m^3}$

The thickness $(h_f)$ and unit weight $()$ of the leveling concrete: $6c\frac{m}{22}k\frac{N}{m^3}$

Live loads for D$101$ and D$103$:$2k\frac{N}{m^2}$

Live loads for D$102$:$3\mathrm{.}5$ kN$/$m

Live loads for D$103$:$5$ kN$/$m$^2$

a$)$ Determine the thickness $($hf$)$ of the slab system.

b$)$ Determine the design load of the slabs $(P_d).$

c$)$ Determine the bending moments at the mid$-$span and the supports of the slabs.

d$)$ Calculate the reinforcement area for each slab and select the suitable reinforcement area considering the codes requirements.