A. 1.8 km/hr
B. 3 km/hr
C. 3.6 km/hr
D. 4 km/hr
Let x be the speed of the river.
Ds = (6 + x) km/hr; Us = (6 – x) km/hr
If t hours is the time to row downstream then 4t hours is the time to row upstream.
(6 + x)*t = (6 – x)*4t
6 + x = 24 – 4x
x = 3.6 km/hr
Related Mcqs:
- A man can row 30 km downstream and 20 km upstream in 4 hours. He can row 45 km downstream and 40 km upstream in 7 hours. Find the speed of man in still water?
A. 15 kmph
B. 10 kmph
C. 12 kmph
D. 12.5 kmph
E. None of these - 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 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 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 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 man can row 9 1/3 km/hr in still water and he finds that is thrice as much time to row u p than as to row down the same distance in river. The speed of the current is:________?
A. 3 1/3 km/hr
B. 3 1/9 km/hr
C. 1 ¼ km/hr
D. 4 2/3 km/hr - A man whose speed is 4.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph, find his average speed for the total journey?
A. 8 kmph
B. 4 kmph
C. 2 kmph
D. 10 kmph - 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 - The speed at which a man can row a boat in still water is 15 kmph. If he rows downstream, where the speed of current is 3 kmph, what time will he take to cover 60 metres?
A. 10 seconds
B. 15 seconds
C. 20 seconds
D. 12 seconds
E. None of these - 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
