A city bus authority fixes the fare for the first kilometre at ₹15 and increases it by ₹0.50 for every subsequent kilometre. The fares thus form an arithmetic progression.
(i) Calculate the fare for a 20 km journey.
(ii) What will a commuter pay for a 40 km journey?
(iii) Determine how many whole kilometres a commuter can travel if he has exactly ₹250 for the fare.