Q. 21 A boat can travel 60 km in 3 hours while going downstream. It can travel 90 km in 5 hours while going upstream. What is the ratio of the speed of boat in still water to the speed of the stream?

Q. 22 The speed of boat in still water is 6 km/hour. Time taken by the boat to cover a certain distance upstream in 3 hours more than the time taken to cover the same distance downstream. If the speed of the stream is 2 km/h, then what is the total distance, upstream and downstream, covered by the boat?

Q. 23 A boat can go 30 km downstream and 24 km upstream in 2 hours 27 minutes also. It can go 10 km downstream and 4 km upstream in 37 minutes. What is the speed of the boat upstream (in km/hour)?

Q. 24 If a boat goes upstream at a speed of 21 km/hour and comes back the same distance at 28 km/hour. What is the average speed (in km/hour) for the total journey?

Q. 25 A boat moves downstream at the rate of 1 km in 7(1/2) minutes and upstream at the rate of 5 km an hour. What is the speed of the boat in the still water?

Q. 27 A boat takes half time in moving a certain distance downstream than upstream. The ratio of the speed of the boat in still water and that of the current is

Q. 28 A boat covers 12 km upstream and 18 km downstream in 3 hours, while it covers 36 km upstream and 24 km downstream in 6(1/2) hours. What is the speed of the current?

Q. 29 A boat goes 4 km upstream and 4 km downstream in 1 hour. The same boat goes 5 km downstream and 3 km upstream in 55 minutes. What is the speed of boat in still water

(A) 6.5 km/h (B) 7.75 km/h (C) 9 km/h (D) 10.5 km/h

Q. 32 A boat travels 60 km downstream and 20 km upstream in 4 hours. The same boat travels 40 km downstream and 40 km upstream in 6 hours. What is the speed of the stream?

Q. 33 A swimmer swims from a point A against a current for 5 minutes and then swims backwards in favour of the current for the next 5 minutes and comes to the point B. If AB is 100 metres, then the speed of the current is

Q. 34 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/h, then the speed of the boat in still water is

Q. 36 A man can row at a speed of 4(1/2) km/h in still water. If he takes 2 times as long to row a distance upstream as to row the same distance downstream, then the speed of stream is

Q. 37 The speed of a motorboat is that of the current of water as 36 : 5. The boat goes along with the current in 5 hours 10 minutes. It will come back in

Q. 38 Two boats A and B start towards each other from two places, 108 km apart. Speed of the boat A and B in still water are 12 km/h and 15 km/h respectively. If A proceeds down and B up the stream, they will meet after

Q. 39 A boat can travel with a speed of 13 km/hr in still water. If the speed of the stream is 4 km/hr in the same direction, then the time taken by boat to go 63 km in opposite direction is

Q. 40 A boat goes 6 km an hour in still water, but takes thrice as much time in going the same distance against the current. The speed of the current is