A man rows to a place 48 km distant and comes back in 14 hours. He finds that he can row 4 km with the stream in the same time as 3 km against the stream. The speed of the stream is:
A. 1.5 km/h
B. 3.5 km/h
C. 1.8 km/h
D. 1 km/h
Answer: Option D
Solution (By Examveda Team)
$$\eqalign{ & {\text{Let, speed of boat}} = x \cr & {\text{Speed of stream}} = y \cr & \Rightarrow \frac{{48}}{{x + y}} + \frac{{48}}{{x - y}} = 14\,.\,.\,.\,.\,.\,\left( {\text{i}} \right) \cr & {\text{and, }}\frac{4}{{x + y}} = \frac{3}{{x - y}} \cr & \frac{{x - y}}{{x + y}} = \frac{3}{4} = \frac{6}{8} \cr & {\text{From equation }}\left( {\text{i}} \right), \cr & \frac{{48}}{8} + \frac{{48}}{6} = 14 \cr & 14 = 14\,\,\,\left( {{\text{Satisfied}}} \right) \cr & {\text{So, }}x - y = 6 \cr & \,\,\,\,\,\,\,\,\,x + y = 8 \cr & \,\,\,\,\,\overline {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,y = 1\,\,} {\text{km/hr}} \cr} $$Related Questions on Boats and Streams
A. 2 hours
B. 3 hours
C. 4 hours
D. 5 hours
E. None of these
A. 8.5 km/hr
B. 9 km/hr
C. 10 km/hr
D. 12.5 km/hr
E. None of these
A. 2 : 1
B. 3 : 2
C. 8 : 3
D. Cannot be determined
E. None of these
A. 4 km/hr
B. 5 km/hr
C. 6 km/hr
D. 10 km/hr

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