Design a simply$-$supported one way slab given the following conditions according to the ACI$318$:

Slab Span $-20$ ft

Uniform Dead Load $($Excluding Self$-$Weight$)-100$ psf

Uniform Live Load $-70$ psf

Compressive Strength of Concrete $-4\mathrm{.}5$ ksi

Yield Strength of Reinforcement $-60$ ksi