$3.$ The cross$-$section of a continuous one$-$way solid slab in a building is shown below. The dead load on the slabs is due to self$-$weight plus $80$ psf ; the live load is $145$ psf$.$ Design the exterior span $($sections a$,$b$,$c$)$ and the first interior span $($sections d$,$e$,$f$)$ of the continuous slab. Design all necessary reinforcement and draw a detailed section.