Explanation: After first half km , each half km costs \(p/8\). Now, for \(1/2\) km the cost is \(p/8\) so, for 1 km the cost is \((p/8)/(1/2)=p/4\). so, for \(\{q-(1/2)\}\) km the cost is \((p/4)*\{q-(1/2)\}=(2pq-p)/8\). So total cost is \((2pq-p)/8+p=(2pq+7p)/8\)