A 300 m. long train passes a pole in 12 secs. What is its speed in km/hour ?

A train runs for 2 hrs at the speed of 35km/hr. It runs for 3 1/2 hrs at the speed of 60km/hr and then runs for 2 1/2 hrs at the speed of 70km/hr. Find the average speed of the train :

A 1km long train passes through a tunnel of 1 km length at a speed of 1 km per minute. How much time will it take to pass through it completely ?

A train moves with a speed of 108km/hr. Its speed in metre per second is: 

 A train travels 42.5 km/hr. How many metres will it travel in 12 minutes 

A train passes through a tunnel with length 500 metres in one minute running at a speed of 72km/hour.If so, what is the length of the train ?