Aptitude - Boats & Streams Online Quiz


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Following quiz provides Multiple Choice Questions (MCQs) related to Boats & Streams. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Questions and Answers

Q 1 - A man columns 30 km downstream and 18 km upstream, taking 5 hours every time. Every time what is the speed of the current?

A - 1.2 km/hr

B - 1 km/hr

C - 2 km/hr

D - 1.5 km/hr

Answer : A

Explanation

Speed downstream = 30/5 km/hr = 6km/hr`Speed upstream = 18/5 km/hr = 3.6 km/hr`Speed of the current = 1/2 (6-3.6) km/hr = 2.4/2 km/hr = 1.2 km/hr

Q 2 - A man can push 30km upstream and 44km downstream in 10 hours. Additionally, he can push 40km upstream and 55km downstream in 13 hours. Discover the rate of flow and the current of the man in still water.

A - 4,5 km/hr

B - 5,6 km/hr

C - 3,8 km/hr

D - 7,9 km/hr

Answer : C

Explanation

Let speed upstream be x km/hr and the velocity downstream be y km/hr`At that point, 30/x+44/y=10 ... (i) and 40/x+55/y=13 ... (ii)`Increasing (ii) by 4, (i) by 5 and subtracting, we get: 10/x=2=>x=5.`Putting x=5in (i) we get 4y=44=> y=11.`∴ Speed upstream =5km/hr, speed downstream=11km/hr.`Velocity of the current =1/2(11-5) km/hr=3km/hr.`Velocity of man in still water =1/2(11+5) km/hr=8km.

Q 3 - A boat goes 24km downstream in 10 hours. It takes 2 hours more to cover the same separation against the stream. What is the rate of the watercraft in still water?

A - 2.2 km/hr

B - 2.8 km/hr

C - 4 km/hr

D - 4.2 km/hr.

Answer : A

Explanation

Speed downstream =24/10 km/hr=2.4 km/hr`Speed upstream =24/12 km/hr =2 km/hr`Speed of the boat in still water=1/2(2.4+2) km/hr=2.2 km/hr.

Q 4 - A watercraft covers a separation of 30km in 5/2 hrs running downstream. While returning, it covers the same separation 15/4hrs .What is the velocity of the watercraft in still water?

A - 8 km/hr

B - 12 km/hr

C - 14 km/hr

D - 10 km/hr.

Answer : D

Explanation

Speed downstream = (30*2/5) km/hr=12km/hr.`Speed upstream= (30*4/15) km/hr=8 km/hr.`Speed of boat in still water=1/2(12+8) km/hr=10 km/hr.

Q 5 - The velocity of a speedboat is that of the flow of water as 36:5. The vessel obliges the current in 5 hours 10min. It will return:

A - 5 hrs 50 min

B - 6 hours

C - 6 hours 50 min

D - 12 hrs 10 min

Answer : C

Explanation

Let the speed of motorboat be 36x km/hr and that of the current of water be 5x km/hr.`Speed downstream = (36x+ 5x) km/hr=41x km/hr,`Speed upstream = (36x-5x) km/hr=31x km/hr.`Distance covers downstream = (41x*31/6) km.`Distance upstream= [(41*31) x/6 * 1/31x] hrs = 41/6 hrs = 6 hrs 50 min.

Q 6 - In a waterway, a man takes 3 hours in paddling 3 km upstream or 15km downstream. What is the rate of the current?

A - 2 km/hr

B - 4 km/hr

C - 6 km/hr

D - 9 km/hr.

Answer : A

Explanation

Speed upstream =3/3 km/hr =1 km/hr.`Speed downstream =15/3 km/hr=5 km/hr.`Speed of current =1/2 (5-1) km/hr =2 km/hr

Q 7 - A vessel goes 6 km in an hour in still water. It requires thrice as much investment in covering the same separation against the current. Velocity of the current is:

A - 16 km/hr

B - 18 km/hr

C - 24 km/hr

D - 28 km/hr.

Answer : B

Explanation

Let the speed of the steamer in still water be x km/hr.`Speed downstream = (x +2) km/hr, speed upstream = (x-2) km/hr.`Then 4 (x+2) = 5 (x-2) => x = 18.`Hence, the speed of the streamer in still water is 18 km/hr.

Q 8 - Aman can push 15/2 kms an hour in still water and he finds that it takes him twice as long to down the stream. The rate of the stream is:

A - 2.4 km/hr

B - 2.5 km/hr

C - 3.4 km/hr

D - 3.5 km/hr

Answer : B

Explanation

Let the rate of stream be x km/hr. Then,`Speed downstream = (15/2 +x) km/hr, Speed upstream = (15/2 - x) km/hr`(15/2 +x) = 2 (15/2 -x) => 3x =15/2 => x = 15/2*3 = 5/2 = 2.5`∴ Rate of stream=2.5 km/hr

Q 9 - The current of a stream keeps running at 4km 60 minutes. A boat goes 6 km and back to the beginning stage in 2hour. The rate of the boat in still water is:

A - 6 km/hr

B - 7.5 km/hr

C - 8 km/hr

D - 6.8 km/hr

Answer : C

Explanation

Let the speed in still water be x km/hr. Then,`Speed downstream = (x+ 4) km/hr, speed upstream = (x-4) km/hr.`6/(x+4) + 6 /(x-4) = 2 => 1/(x+4) +1/(x-4)=2/6 =1/3 =>(x+4)+(x-4)/x2-16=1/3 =>x2-16=6x`=> x2 -6x-16=0=> (x-8) (x+2) = 0 => x = 8.

Q 10 - The current of a stream keeps running at 4km 60 minutes. A boat goes 6 km and back to the beginning stage in 2hour. The rate of the boat in still water is:

A - 6 km/hr

B - 7.5 km/hr

C - 8 km/hr

D - 6.8 km/hr

Answer : C

Explanation

Let the speed in still water be x km/hr. Then,`Speed downstream = (x+ 4) km/hr, speed upstream = (x-4) km/hr.`6/(x+4) + 6 /(x-4) = 2 => 1/(x+4) +1/(x-4)=2/6 =1/3 =>(x+4)+(x-4)/x2-16=1/3 =>x2-16=6x`=> x2 -6x-16=0=> (x-8) (x+2) = 0 => x = 8.∴ Speed of boat in still water = 8 km/hr.


aptitude_boats_streams.htm

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