A. 15 kmph
B. 10 kmph
C. 12 kmph
D. 12.5 kmph
E. None of these
Explanation:
Let the speed of the man in still water be a kmph and let the speed of the stream be b kmph.
Now 30/(a + b) + 20/(a – b) = 4 and 45/(a + b) + 40/(a – b) = 7
Solving the equation, the speed of man in still water is 12.5 kmph.
Related Mcqs:
- The time taken by a man to row his boat upstream is twice the time taken by him to row the same distance downstream. If the speed of the boat in still water is 42 kmph, find the speed of the stream?
A. 12 kmph
B. 13 kmph
C. 14 kmph
D. 15 kmph - A man rows at a speed of 6 km/hr in still water. If the time taken to row a certain distance upstream is 4 times the time taken to row the same distance downstream, what is the speed of the river?
A. 1.8 km/hr
B. 3 km/hr
C. 3.6 km/hr
D. 4 km/hr - A man can row downstream at 18 kmph and upstream at 10 kmph. Find the speed of the man in still water and the speed of stream respectively?
A. 13, 3
B. 12, 6
C. 15, 3
D. 14, 4 - A boats man can row in still water at speed of 7 km/hr. It takes 6 hours more to travel the same distance in upstream than in downstream if the speed of the river is 3 km/hr. what is the distance between the two destinations?
A. 20 km
B. 40 km
C. 30 km
D. 10 km - A man can row upstream at 25 kmph and downstream at 35 kmph, and then find the speed of the man in still water?
A. 60 kmph
B. 10 kmph
C. 30 kmph
D. 5 kmph - A boat running upstream takes 8 hours 48 min to cover a certain distance while it takes 4 hours to cover the same distance running downstream. What is the ratio between the speed of the boat and the speed of water current respectively?
A. 2 : 1
B. 3 : 1
C. 8 : 3
D. Cannot be determined - A man swims downstream 30 km and upstream 18 km taking 3 hours each time, what is the speed of the man in still water?
A. 2 kmph
B. 8 kmph
C. 16 kmph
D. 4 kmph - The speed of a boat in upstream is 60 kmph and the speed of the boat downstream is 80 kmph. Find the speed of the boat in still water and the speed of the stream?
A. 70, 10 kmph
B. 35, 27 kmph
C. 50, 60 kmph
D. 45, 55 kmph - A man can row a boat at 20 kmph in still water. If the speed of the stream is 6 kmph, what is the time taken to row a distance of 60 km downstream?
A. 20/6 hours
B. 27/2 hours
C. 30 hours
D. 30/13 hours - A boat running downstream covers 24 km’s in 4 hours while for covering the same distance upstream it takes 6 hours whats the speed of the boat in still water?
A. 3.5km/hr
B. 5.5 km/hr
C. 6 km/hr
D. Data Inadequate
E. None of these
