Bunuel
A man rows for 3 hrs downstream and then for 3 hrs upstream. In this whole process he covers a distance of 12 kms. If the speed of the stream is 1 kmph, for how much more time will he have to row upstream to reach the starting point?
A. 6 hr
B. 5 hr
C. 4 hr
D. 3 hr
E. 2 hr
Are You Up For the Challenge: 700 Level QuestionsGiven: A man rows for 3 hrs downstream and then for 3 hrs upstream. In this whole process he covers a distance of 12 kms.
Asked: If the speed of the stream is 1 kmph, for how much more time will he have to row upstream to reach the starting point?
Let the speed of the boat in still water be x kmh
A man rows for 3 hrs downstream and then for 3 hrs upstream. In this whole process he covers a distance of 12 kms.
3(x+1) + 3(x-1) = 12 (1)
x = 2 kmh
Downstream distance - Upstream distance = 3(2+1) - 3(2-1) = 9 - 3 = 6 km
Time will he have to row upstream to reach the starting point = 6/(2-1) = 6 hours
IMO A