A train travels 20% faster than a car. Both start from point A at the same time and reach point B, 180 km away at the same time. On the way the train takes 30 minutes for stopping at the stations. What is the speed (in km/hr) of the train?
1). 56
2). 66
3). 72
4). 80
Let the speed of the car be a km/hr
⇒ Speed of the train = a + (20/100)a = 1.2a km/hr
⇒ Total distance covered by both = 180 km
⇒ Time taken by train = 180 km/1.2a = 150/a hr
⇒ Time taken by car = 180/a hr
Given: both take equal amount of time when train has 1/2 hr of stoppage time
⇒ 150/a + 1/2 = 180/a
⇒ 30/a = ½
⇒ a = 60 km/hr
Hence, speed of train = 1.2a = 72 km/hr
∴ the correct option is 3)