A man covered a certain distance at some speed. Had he moved 3 km per hour faster, he would have taken 40 minutes less. If he had moved 2 km per hour slower, he would have taken 40 minutes more. The distance (in km) is: 

A person goes to his office by scooter at the speed of 80 km/hr and reaches 60 minutes earlier. If he goes at the speed 50 km/hr, then he reaches 48 minutes late. What will be the speed of the scooter to reach on the usual time?

A man sets out on a journey. He traveled for a total of 16 hours. He covered the first half of the distance at a speed of 40 km per hour and the second half at a speed of 60 km per hour. How much distance did he cover?

A policeman starts to chase a thief. When the thief goes 10 steps the policeman moves 8 steps and 5 steps of the policeman are equal to 7 steps of the thief. The ratio of the speeds of the policeman and the thief is: 

I walk a certain distance and ride back taking a total time of 37 minutes. I could walk both ways in 55 minutes. How long would it take me to ride both ways?

A bus can travel $$ 12{2\over5}$$ Km in one hour. How much distance will it cover in $$ 2{3\over4}$$ hours? 

A 160-meter-long train running at a speed of 90 km/h crosses a platform is 18 s. What is the length of the platform in metre?