Please wait...

Boat & Stream Test 255
Result
Boat & Stream Test 255

  • /

    Score

  • -

    Rank
Time Taken: -
  • Question 1/10
    1 / -0.25
    A boat takes 4 hours 24 minutes and 2 hours 30 minutes to cover a same distance in upstream and downstream respectively. What is the ratio between the speed of the boat in still water and speed of the current respectively?
    Solutions

    Let the speed in downstream and upstream be x and y respectively

    Distance = Speed × Time

    Distance is same

    According to the question,

    (x) × 5/2 = y × 22/5

    x = 44y/25

    Speed of boat in still water = (x + y)/2 = (44y/25 + y)/2 = 69y/50

    Speed of current = (x – y)/2 = (44y/25 – y)/2 = 19y/50

    Required ratio = (69y/50) : (19y/50) = 69 : 19.

  • Question 2/10
    1 / -0.25
    Speed of a boat in upstream is 30 km/hr. If the speed of stream is 5 km/hr, then how much distance will it cover in 2 hours in downstream?
    Solutions
    Speed of a boat in upstream = 30 km/hr.

    Speed of stream = 5 km/hr

    Speed of boat in still water = 30 km/hr + 5 km/hr = 35 km/hr

    Now, Speed of a boat in downstream = 35 km/hr + 5 km/hr = 40 km/hr

    Time = 2 hours

    Required distance =

  • Question 3/10
    1 / -0.25
    A swimmer swims 1 km downstream in 5 minutes and 1 km upstream in 12 minutes. What is the speed of current?
    Solutions
  • Question 4/10
    1 / -0.25
    A Boat rowed down the river at 7 Km/h and rowed up the river at 3 km/h. What is the velocity of stream?
    Solutions
    B + W = 7
    B – W = 3
    W =
    W = 2 km/h
  • Question 5/10
    1 / -0.25
    Speed of a boat in still water is 12 kmph and that of the current is 3 kmph. A man rows a boat upstream up to 135 km and returns downstream to the starting point. Find the total time taken for the entire journey in hours.
    Solutions
    Speed of boat in still water (x) = 12 kmph

    Speed of current (y) = 3 kmph 

    Speed of boat during upstream (x-y)= 12 – 3 = 9 kmph

    Speed of boat during downstream(x+y) = 12+3 = 15 kmph

    A man rows a boat upstream up to 135 km and returns downstream to the starting point.

    Required Time =  kmph

  • Question 6/10
    1 / -0.25
    A boat sails downstream from point A to point B, which is 20 km away from A, and then returns to A. If the actual speed of boat (in still water) is 3 km/hr then the trip from A to B takes 16 hrs less than that from B to A. What must be the speed of the boat for the trip to take exactly 80 minutes in travelling from A to B.
    Solutions

    Let speed of stream = x km/hrs

    Given,

    Or, 20

    40x = 144-16x2

    2x2+5x-18= 0

    On solving…. X= 2km/hr.

    Let the speed of the boat for the trip from A to B to take exactly 80 minutes =y

    Now,

    15 =y+2

    Y =13km/hr.

  • Question 7/10
    1 / -0.25
    Speed of a swimmer in still water is 8 km/h. He went downstream to a certain distance. While coming back to the initial point he realized that he will take thrice the time to reach the initial point than he earlier took for downstream. What is the speed of current?
    Solutions
    Let the speed of the current is C and T be the total time taken to travel the distance in the downstream. 

    Since the distance travelled in both downstream and downstream is same,
    ⇒ (8 - C) x 3T = (8 + C) x T
    ⇒ 24 - 3C = 8 + C
    ⇒ 16 = 4C

    we get,
    ⇒ C = 4kmph
  • Question 8/10
    1 / -0.25
    A man swims downstream a distance of 15 km in 1 hour. If the speed of the current is 5 km/hour, the time taken by the man to swim the same distance upstream is
    Solutions

    Let the speed of man in still water be x kmph.

     Time taken in swimming upstream

  • Question 9/10
    1 / -0.25
    The speed of boat in still water is 50 km/hr and the speed of current is 14 km/hr. If a boat goes from A to B and return from B to A, it takes 6 hrs 15 minutes total time. Find the time taken by boat to cover twice the distance down- stream?
    Solutions

    Ratio of down-stream(D) and up-stream is

    = (50+14) : (50-14)

    = 64 : 36 = 16 : 9

    So time will be opposite i.e. 9:16

     (9+16)  6×60+15

     25360+15  25375 115 minute

     Downstream time= 15×9 = 135 minutes = 2 hrs 15 min.

    So, time taken to cover double distance in Downstream = 2 × 2hr 15 min. = 4.5 hrs

    Hence, option D is the correct answer.

  • Question 10/10
    1 / -0.25
    Two cities P and Q are 360 km apart and river flows downstream from P to Q. Two boats A and B start simultaneously from P and Q respectively towards Q and P respectively. The still water speeds of P is 25 km/h and that of Q is 15 km/h. When do the two boats meet if river flows at 5 km/h?
    Solutions
    Effective speed of boat moving downstream = 25 + 5 = 30 km/h
    Effective speed of boat moving upstream = 15 – 5 = 10 km/h
    The boats approach each other at 30 + 10 = 40 km/h
    Hence, the time taken to meet = 360/40 = 9 hours
User Profile
-

Correct (-)

Wrong (-)

Skipped (-)

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
Get latest Exam Updates
& Study Material Alerts!
No, Thanks
Click on Allow to receive notifications
×
Open Now