41). A boat running upstream takes 528 min to cover a certain distance, while it takes 240 min to cover the same distance running downstream. What is the ratio between the speed of the boat and speed of the water current, respectively?
| A). 2 : 1 |
| B). 3 : 2 |
| C). 8 : 3 |
| D). Couldn't be determined |
|
42). A river is flowing with a steady speed of 4 km/h. One rows his boat downstream in the river and then returns by rowing upstream in the same river. When he returns to the starting point, the total distance covered by him is 42 km. If the return journey takes 2 h more than his outward journey, then the speed of his rowing in still water must be
| A). 12 km/h |
| B). 10 km/h |
| C). 9 km/h |
| D). 8 km/h |
|
43). The ratio of speeds of a motorboat to that of the current of water is 36 : 5. The motorboat goes along with the current in 5 h 10 min. Find the time to come back of motorboat.
| A). 5 h 50 min |
| B). 6 h |
| C). 6 h 50 min |
| D). 12 h 10 min |
|
44). Ishwar is rowing a boat. He takes half time in moving a certain distance downstream than upstream. What is the ratio of the rate of boat in still water to the rate of current?
| A). 2 : 1 |
| B). 5 : 1 |
| C). 7 : 1 |
| D). 3 : 1 |
|
45). In a river, the ratio of the speed of stream and speed of a boat in still water is 2 : 5. Again, ratio of the speed of stream and speed of an another boat in still water is 3 : 4. What is the ratio of the speeds of the first boat to the second boat in still water?
| A). 10 : 7 |
| B). 15 : 8 |
| C). 4 : 3 |
| D). 5 : 4 |
|
46). A motorboat travelling at the some speed, can cover 25 km upstream and 39 km downstream in 8 h. At the Same speed, it can travel 35 km upstream and 52 km downstream in 11 h. The speed of the stream is
| A). 2 km/h |
| B). 3 km/h |
| C). 4 km/h |
| D). 5 km/h |
|
47). A boat covers 24 km upstream and 36 km downstream in 6 h, while it covers 36 km upstream and 24 km downstream in \( 6\frac{1}{2} \) h. The speed of the current is
| A). 1 km/h |
| B). 2 km/h |
| C). 1.5 km/h |
| D). 2.5 km/h |
|
48). A, B and C are situated at the bank of river which is flowing at a constant rate. B is at an equal distance with A and C. A swimmer Avinash takes 10 h to swim from A to B and B to A. Also, he takes 4h to swim from A to C. What is the ratio of speed of Avinash in still water and speed of stream?
| A). 5 : 3 |
| B). 3 : 5 |
| C). 2 : 5 |
| D). 1 : 2 |
|
49). A river is flowing at a speed of 5 km/h in a particular direction. A man, who can swim at a speed of 20 km/h in still water, starts swimming along the direction of flow of the river from point A and reaches another point B which is at a distance of 30 km from the starting point A. On reaching point B, the man turns back and starts swimming against the direction of flow of the river and stops after reaching point A. The total time taken by the man to complete his journey is
| A). 2 h 30 min |
| B). 3 h 12 min |
| C). 3 h 30 min |
| D). 3 h 45 min |
|
50). When the speed of a boat in still water is 4 km/h and the rate of stream is 2 km/h, find upstream speed of the boat.
| A). 6 km/h |
| B). 5 km/h |
| C). 2 km/h |
| D). 7 km/h |
|
