Bus Problem Questions

Two cities X and Y are connected by a regular bus service with a bus leaving in either direction every T min. A girl is driving scooty with a speed of $60\text{km/h}$ in the direction X to Y notices that a bus goes past her every $30\text{minutes}$ in the direction of her motion, and every $10\text{minutes}$ in the opposite direction. Choose the correct option for the period T of the bus service and the speed (assumed constant) of the buses.