1. Rajesh rows in still water with a speed of 4.5 kmph to go to a certain place and comes back. Find his average speed for the whole journey, if the river is flowing with a speed of 1.5 kmph?
2. Find the speed of stream if a boat covers 36 km in downstream in 6 hours which is 3 hours less in covering the same distance in upstream?
3. Sravan drove from home to a neighboring town at the speed of 50 km/h and on his returning journey, he drove at the speed of 45 km/h and also took an hour longer to reach home. What distance did he cover?
4. A motorboat takes half time to cover a certain distance downstream than upstream. What is the ratio between rate of current and rate of boat in still water?