Boat and Stream Practice Question and Answer
8Q: A man went downstream for 28 km in a motor boat and immediately returned. It took the man twice as long to make the return trip. If the speed of the river flow were twice as high, the trip downstream and back would take 672 minutes. Find the speed of the boat in still water and the speed of the river flow. 52327 05b5cc672e4d2b4197774c0c8
5b5cc672e4d2b4197774c0c8- 112 km/hr, 3 km/hrfalse
- 29 km/hr, 3 km/hrtrue
- 38 km/hr, 2 km/hrfalse
- 49 km/hr, 6 km/hrfalse
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Answer : 2. "9 km/hr, 3 km/hr"
Explanation :
Answer: B) 9 km/hr, 3 km/hr Explanation: Let the speed of the boat = p kmph Let the speed of the river flow = q kmph From the given data, 2 x 28p + q = 28p - q => 56p - 56q -28p - 28q = 0 => 28p = 84q => p = 3q. Now, given that if 283q + 2q + 283q - 2q = 67260=> 285q + 28q = 67260=> q = 3 kmph=> x =3q = 9 kmph Hence, the speed of the boat = p kmph = 9 kmph and the speed of the river flow = q kmph = 3 kmph.
Q: Ratio of time taken by a sailor to cover some distance upstream and downstream is 4 : 1. If speed of stream is 4.5 km/hr. Then find out speed of boat?
6343 05e8b071f67af633f22bda983
5e8b071f67af633f22bda983- 18.5 km / hrfalse
- 29.5 km / hrfalse
- 37.5 km / hrtrue
- 48 km / hrfalse
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Answer : 3. "7.5 km / hr "
Q: A swimmer can swim 68 km downstream and 45 km upstream in 9 hours and he will take 2 hours more to swim 51 km downstream and 72 km upstream. Find the speed of the swimmer in still water.
5745 0608fb6257748471dd98ccd2a
608fb6257748471dd98ccd2a- 117false
- 215false
- 313true
- 49false
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Answer : 3. "13"
Q: A man rows to a place 35 km in distance and back in 10 hours 30 minutes. He found that he can row 5 km with the stream in the same time as he can row 4 km against the stream. Find the rate of flow of the stream?
4101 05f23edc41436461f6a2f678f
5f23edc41436461f6a2f678f- 11.33 km/hrfalse
- 21.5 km/hrfalse
- 31 km/hrfalse
- 40.75 km/hrtrue
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Answer : 4. "0.75 km/hr"
Q: 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.
3198 05f2394884e7e0d508b57ac0d
5f2394884e7e0d508b57ac0d- 14.5 hr.false
- 26 hr.true
- 39 hr.false
- 47 hr.false
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Answer : 2. "6 hr. "
Q: A man can row with the stream at 9 km/hr. and against the stream at 3 km/hr. His speed in still water is -
2640 0608fc0278ab61162923103bb
608fc0278ab61162923103bb- 112 km/hrfalse
- 25 km/hrfalse
- 310 km/hrfalse
- 46 km/hrtrue
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Answer : 4. "6 km/hr"
Q: A motorboat, whose speed is 45 km./hr. in still water goes 180 km. downstream and comes back in a total of 9 hours. The speed of the stream (in km/hr.) is-
1973 05e96c3fa3d565c17b6031218
5e96c3fa3d565c17b6031218- 112false
- 221false
- 318false
- 410false
- 515true
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Answer : 5. "15"
Q: If a sailer sails 12 km distance within 5 hours against the flow of a river. If he sails 22 km distance in same time along the flow of the river. Then velocity of the river is _______
1819 05e788081948fba6459010c46
5e788081948fba6459010c46- 11 km / hourtrue
- 22 km / hourfalse
- 31.5 km / hourfalse
- 42.5 km / hourfalse
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