Town X is 180km away from Town Z. A bus started travelling from Town X at 11.30am and travelled towards Town Z. Half an hour later, a car started from Town X, travelling at an average speed of 75km/h along the same route. The car overtook the bus and reached Town Z before the bus. The bus reached Town Z at 2.30 pm.
(a) At what time did the car overtake the bus?
(b) How far away was the bus from Town Z when the car reached Town Z?