A cyclist cycles 8 km at 15 km/hr and a further 4 km at 20 km/hr. Find the average speed in km/hr. 

A man can swim to a place 120 km distant and come back in 35 hours. He finds that he  can swim 6 km against the stream in the same time as 8 km with the stream. Find the ratio of speed of man in still water to that of stream?

The ratio between speed of boat in down stream and speed of stream is 9 : 1. If the speed of current is 3 km/hr, then find the distance travelled in upstream in 5 hours. 

A man left 9 minutes early than the scheduled time and in order to reach the destination 378 km away in time, it has to slow its speed by 6 km/h from the usual. What is the usual speed (in km/hr.) of the man?

A car travelled 80% of the distance from town A to B by traveling at T hours at an average speed of V km/h. The car travels at an average speed of S km/h for the remaining part of the trip. Which of the following expressions represents the average speed for the entire trip?

Nihal walks with 12 km/h after every km, he takes the rest for 12 min after every kilometer. How much time will he take to cover 36 km distance.

In a 1500 m race, Chaitali beats Vrunali by 100 m and in 1200 m race, Vrunali beats Krutika by 75 m. If Chaitali and Krutika are compared, then for how much m Chaitali will beat Krutika in 900 m race?

A 275 m long train crosses a platform of equal length in 33 s. What is the speed of the train in km/h?