11. A boat takes 19 hours for travelling downstream from point A to point B and coming back to a point C midway between A and B. If the velocity of the stream is 4 kmph and the speed of the boat in still water is 14 kmph, what is the distance between A and B ?
A. 160 km B. 180 km
C. 200 km D. 220 km
12.A boat running upstream takes 8 hours 48 minutes to cover a certain distance, while it takes 4 hours 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. Cannot be determined
E. None of these
13. A man can row 9 and 1/3 kmph in still water and finds that it takes him thrice as much time to row up than as to row, down the same distance in the river. The speed of the current is . [Central Excise ]
3 and 1/3 km/hr 4 and 2/3 km/hr
3 and 1/9 km/hr 14 km/hr
14. A boat running downstream covers a distance of 16 km in 2 hours while for covering the same distance upstream, it takes 4 hours. What is the speed of the boat in still water ?
A. 4 km/hr B. 6 km/hr
C. 8 km/hr D. Data inadequate
15. | A man can row 7 ½kmph in still water. If in a river running at 1.5 km an hour, it takes him 50 minutes to row to a place and back, how far off is the place? |
| · A. 3 km · B. 4 km · C. 5 km · D. 6 km
|
16.A boatman can row 2 km against the stream in 20 minutes and return in 18 minutes. Find the rate of current
[A] 1/3 km/hr
[C] 5/3 km/hr
[B] 2/3 km/hr
[D] None of these
|
|
17. | A man can row three-quarters of a kilometre against the stream in 11 1/4 minutes. The speed (in km/hr) of the man in still water is: |
| · A. 4 1/4 km/hr · B. 5 km/hr · C. 6 km/hr · D. 7 km/hr
|
18. | A man can row upstream at 8 kmph and downstream at 13 kmph. The speed of the stream is |
| A. 2.5 km/hr | B. 4.2 km/hr | |
| C. 5 km/hr | D. 10.5 km/hr | |
19. If a man can swim downstream at 6 kmph and upstream at 2 kmph, his speed in still wateris : . [Assistant Grade]
4 km/hr 3 km/br
2 km/hr 2.5 km/hr
20.The speed of the boat in still water in 12 kmph. It can travel downstream through 45 kms in 3 hrs. In what time would it cover the same distance upstream?
[A] 3
[C] 6
[B] 5
[D] 3
