Speed of a boat in still water is 6 km/hr and speed of the current is 2 km/hr. If boat takes four hours more in upstream than in the downstream to cover ‘D’ km, then find time take by boat to cover ‘D’ km in still water?

A boat can row 15 km per hour downstream and 9 km per hour upstream. The speed (in km/hour) of the boat in still water is:

Speed of current is 10% of speed of boat in still water and the time taken by the boat to cover X km in downstream is 100% more than time taken by the boat to cover (X-45) km in upstream. Find the value of X?

A boat running upstream takes 7 hours and 40 minutes to cover a certain distance while it takes 5 hours to cover the same distance downstream. What is the ratio between the speed of the current and speed of the boat respectively? 

A person rows a distance of $$ {3{3\over4}{ \ km}}$$ upstream in $$ {1{1\over 2}{\ hours}}$$ and a distance of 13 km downstream in 2 hours. How much time ( in hours) will the person take to row a distance of 90 km in still water?

A motorboat covers a certain distance downstream in a river in 3 hours. It covers the same distance upstream in 3 and half an hour. If the speed of the water is 1.5 km / h, then the speed of the boat in still water is: 

A boat goes 12 km downstream and comes back to the starting point in 3 hours. If the speed of the current is 3 km/hr, then the speed (in km/hr) of the boat in still water is : 

The distance between AB is 174 km. Two Boats Start moving towards each other at the same time at points A and B respectively. One in upstream and other in downstream. If their speed in still water is 9.6 km/ hr. and 19.4 km/ hr. respectively. Then in how much time they will meet.