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Aptitude - Boats & Streams Online Quiz
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.
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?
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 - In a stream running at 2 km/hr, a speedboat goes 10km upstream and back again to the beginning stage in 55 min. discover the velocity the speedboat in still water.
Answer : C
Explanation
Let the pace of the speedboat in still water be x km/hr.`Speed downstream =(x+2) km/hr, speed upstream =(x-2) km/hr.`∴ 10/(x-2) +10/(x+2) =55/60=>1/(x-2) +1/(x+2) =55/600=11/120`=> (x+2) +(x-2)/(x-4) =11/120=>11(x2-4) =240x`=>11x2-240x-44=0`=>11x2-242x+2x-44=0`=> 11x(x-22) +2(x-22) =0`=>(x-22) (11x+2) =0=> x=22.`Velocity of speedboat in still water=22km/hr.
Q 3 - A boat is paddled downstream at 15.5km/hr and upstream at 8.5km/hr. The rate of the stream is:
Answer : A
Explanation
Speed downstream =15.5km/hr, Speed upstream =8.5km/hr.`Speed of the stream=1/2(15.5-8.5) km/hr=3.5 km/hr
Q 4 - A boat running downstream covers a separation of 10km in 2 hours .While returning upstream the boat takes 5 hours to cover the same separation. In the event that the velocity of the current and flow is 1.5 kmph, what is the speed of the boat in still water?
Answer : B
Explanation
Speed downstream =10/2 km/hr=5 km/hr.`Speed upstream =10/5 km/hr = 2 km/hr.`Speed of boat in still water = 1/2 (5+2)km/hr=3.5km/hr.
Q 5 - The pace of a watercraft in still water is 15km/hr. It can go 30 km upstream and return downstream to the first point in 4hrs 30min. The velocity of the stream is:
Answer : A
Explanation
Let the speed of the stream be x km/hr.`Speed downstream= (15+x) km/hr, Speed upstream= (15-x) km/hr`30/ (15+x) + 30/ (15-x) = 54/60 => 30/ (15+x) + 30/ (15-x) =9/2.`=> 1/ (15+x) + 1/ (15-x) = 9/2*30= 3/20`=> (15-x) + (15+x) / (15+x) (15-x) = 3/20.`=> 3 (225-x2) = 600 => 3x2 = 75`=> x2 = 25 => x=5.`Speed of stream = 5 km/hr.
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?
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:
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 - A fisher man can push 2km against the stream in 20 min. what's more, return in 15min. What is the rate of the current?
Answer : A
Explanation
Speed upstream = (2/20*60) km/hr = 6 km/hr`Speed downstream = (2/15*60) km /hr = 8km/hr`Speed of the current = 1/2 (8 - 6) km /hr = 1 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:
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:
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.