A train traveling at 100 km an hour takes 3 seconds to enter a tunnel and an additional thirty seconds to pass completely through it. Find the length, in kilometers, of the train. Express your answer as a common fraction. Thank you so much!!!!!
If it took the train 3 seconds to disappear into the tunnel travelling at 100 km/h, that means it travelled its length in 3 seconds. So, its length is simply: its speed x time it disappeared into the tunnel: Or: 100 km/h * 3/3600 =0.083333..... =1 / 12 km - Length of the train.