Composing Functions at a Point

The final cost, $C$, depends on the original discount, $d$, which is based on the clearance price, $p$. (Or the clearance price $p$, determines the original discount and the final cost is half of the clearance price.)

The final cost, $C$, depends on the clearance price, $p$, which is based on the original discount, $d$. (Or the original discount $d$, determines the clearance price and the final cost is half of the clearance price.)

The final cost, $C$, is half $(50\%)$ off the clearance price $p$.

There is no way to interpret this with the information given.