A farmer connects a pipe of internal diameter 25 cm from a canal into a cylindrical tank in his field, which is 12 m in diameter and 2.5m deep. If water flows through the pipe at the rate of 3.6 km/hr, in how much time will the tank be filled ? Also, find the cost of water if the canal depertment charges at the rate of ₹ 0.07 per `m^(3)`.