1. Home
  2. Quantitative Aptitude
  3. Boats and Streams
NumbersHCF and LCMFractionsSimplificationSquare and Cube RootAverageProblems on AgesSurds and IndicesPercentageProfit and LossRatio and ProportionPartnershipTime and WorkPipes and CisternTime and DistanceProblems on TrainsBoats and StreamsAlligation or MixtureSimple InterestCompound InterestLogarithmAreaVolume and Surface AreaRaces And GamesCalendarClocksPermutation and CombinationProbabilityDiscountHeight and DistanceAlgebraTrianglesTrigonometry

Boats and Streams- Aptitude Questions and Answers

View in English View in Hindi

If a man rows at 5 km/hr in still water and 3.5 km/hr against the current,then his rate along the current is ?

A)
8.5 km/hr

B)
6.5 km/hr

C)
6 km/hr

D)
4.25 km/hr


Correct Answer :

6.5 km/hr


Explanation :

If The speed of boat or boatman in calm water is u kmph and The speed of water or stream is v kmph, then:In water, the speed along with stream= (u + v) kmph

Speed of current = 5 - 3.5 = 1.5 km/hr.

So the speed of man along the current = 5 + 1.5 = 6.5 km/hr

The speed of a boat downstream is 15 km/hr and the speed of the stream is 1.5 km/hr. The speed of the boat upstream is ?

A)
13.5 km/hr

B)
16.5 km/hr

C)
12 km/hr

D)
8.25 km/hr


Correct Answer :

12 km/hr


Explanation :

If The speed of boat or boatman in calm water is u kmph and The speed of water or stream is v kmph, then:
Speed downstream= (u + v) kmph , In water, the speed along with stream
Speed upstream = (u - v) kmph ,In water, the speed against the stream

15= u + 1.5
⇒ u = 13.5

Speed upstream, u - v = (13.5 - 1.5) km/hr = 12 km/hr

A boat goes 14 km upstream in 56 minutes. The speed of stream is 2 km/hr. The speed of boat in still water is ?

A)
6 km/hr

B)
15 km/hr

C)
14 km/hr

D)
17 km/hr


Correct Answer :

17 km/hr


Explanation :

Speed upstream Speed(S) = Distance(d)/Time(t) = 14/56 km/min = 14*60/56 km/hr= 15 km/hr

If The speed of boat or boatman in still water is U kmph and The speed of water or stream is V kmph, then:
Speed upstream = (U - V) kmph ,In water, the speed against the stream
15 = U - 2
So speed of boat in still water , U = 17 km/hr

A man can row upstream 32 km in 4 hours. If the speed of current is 2 km/hr, find how much he can go downstream in 6 hours ?

A)
70 km

B)
72 km

C)
64 km

D)
81 km


Correct Answer :

72 km


Explanation :

Upstream Speed(S) = Distance(d)/Time(t) = 32/4 km/hr= 8 km/hr

If The speed of boat or boatman in still water is U kmph and The speed of water or stream is V kmph, then:
Speed upstream = (U - V) kmph
8 = U - 2
Speed of man in still water,U = 8 + 2 = 10 km/hr

Speed of man in downstream = (U + V) kmph = (10 + 2) = 12 km/hr
Now, man cover the distance in 6 hours = 12 * 6 = 72 km

A man can row upstream at 15 km/h and downstream at 21 km/h. The speed of water current of the river is ?

A)
8 km/h

B)
6 km/h

C)
3 km/h

D)
5 km/h


Correct Answer :

3 km/h


Explanation :

If the speed downstream is x kmph and the speed upstream is y kmph, then:
Rate of stream = 1/2 (x - y) kmph.

= 1/2(21 - 15) km/h
= 3 km/h

A man rows downstream 60 km and upstream 36 km, taking 4 hours each time. The speed of the man is :

A)
15 km/h

B)
16 km/h

C)
8 km/h

D)
12 km/h


Correct Answer :

12 km/h


Explanation :

If the speed downstream is x kmph and the speed upstream is y kmph, then:
Speed in still water = 1/2 (x + y) kmph.

x = 60/4 =15 km/h
y = 36/4 = 9 km/h
speed of the man = (15 + 9) / 2 = 12 km/h

The speed of a boat in still water is 15 km/hr and the rate of current is 3 km/hr. The distance travelled downstream in 12 minutes is?

A)
1.2 km

B)
1.8 km

C)
2.4 km

D)
3.6 km


Correct Answer :

3.6 km


Explanation :

Speed Downstream = (15 + 3) km/hr = 18 km/hr.

Distance travelled =(18 * 12 / 60 )hrs = 3.6 km

The speed of a boat in downstream is 12 km / h and in upstream is 8 km / h. The time taken by boat to cover 24 km in still water?

A)
2 hours

B)
3 hours

C)
2.4 hours

D)
1.2 hours


Correct Answer :

2 hours


Explanation :

If The speed of boat or boatman in still water is U kmph and The speed of water or stream is V kmph, then:
Speed upstream = (U - V) = 8 km/hr
Speed of man in downstream = (U + V) kmph = 12 km/hr

After solving above equations 2*U = 20 km/hr
speed of boat in still water is,U = 10 km/hr

Required time = 24 / 10 = 2.4 hr

Relevant links

Boats and Streams - Important Formulas,Tricks and Examples

Latest Updates

Trigonometry

What is the value of cot 4π/3 ?
Indian Politics

Article-24 of the Indian Constitution ‘Prohibition of employment of children in factories, etc’ deals with?

Article-134A of the Indian Constitution ‘Certificate for appeal to the Supreme Court’ deals with?
Chemistry

Who invented Aspirin?
Physics

A larger force on a rotating body results in larger?

What is the unit of the physical quantity, magnetic flux density?
Algebra

The system of equations 2x + 4y = 6 and 4x + 8y = 8 is ?
Time and Distance

A thief is spotted by a policeman from a distacne of 100 m. When the policeman starts the chase, the thief also starts running. If the speed of the theif is 8 km / hour and that of the policeman is 10 km/hour, then how far will the theif have to run before he is overtaken?
Algebra

Aman and Alok attempted to solve a quadratic equation. Aman made a mistake in writing down the constant term and ended up in roots (4, 3). Alok made a mistake in writing down the coefficient of x to get roots (3, 2). The correct roots of the equation are?
Compound Interest

The effective annual rate of interest corresponding to a nominal rate of 22% per annum payable half-yearly is?
Volume and Surface Area

If the volume of a cylinder is 2156 cubic cm and height is 14 cm, find its radius?
Algebra

What is the equation of the line which passes through the points (2, 3) and (- 4, 1)?
Triangles

In △ABC, the angle bisector of ∠A cuts BC at E. Find length of AC, if lengths of AB, BE and EC are 9 cm, 3.6 cm and 2.4 cm?

In a triangle, the length of the opposite side of the angle which measures 45° is 8√2 cm, what is the length of the side opposite to the angle which measures 90°?
General Knowledge of India

The boundary line between India and Pakistan is called?

Which city is located on the banks of the river Mahanadi?
Indian History

When was the battle of Haldighati fought?

In 1498, which Portuguese explorer discovered a new sea route from Europe to India?
General Knowledge of India

Chapchar Kut is a festival of which State?
Chemistry

In chemistry, soap is a salt of a ?
Indian Economy

Which of the following is a Direct tax?
Biology

Sauria lacertidae is the scientific name of?

Which of the following is a primary function of haemoglobin?
Average

A factory buys 8 machines.3 Machine A, 2 Machine B and rest Machine C. Prices of the machines are 100000, 80000 and 45000 respectively.Calculate the average cost of these machines?
Discount

Ticket for an adult is 500 and a child is 200. 1 child goes free with two adults. If a group has 20 adults and 8 children what will be the discount the group get?