A) 2 km/hr
B) 3 km/hr
C) 4 km/hr
D) 5 km/hr
E) 6 km/hr(c)
Correct Answer: D
Solution :
Upstream speed\[=\frac{3}{4}\div \left( \frac{45}{4\times 60} \right)\] \[=\frac{3}{4}\times \frac{4\times 60}{45}=4\,\,km/hr\] Downstream speed\[=\frac{3}{4}\div \left( \frac{15}{2\times 60} \right)\] \[=\frac{3}{4}\times \frac{2\times 60}{15}=6\,\,km/hr\] Speed of man in still water \[=\frac{4+6}{2}=5\,\,km/hr\]You need to login to perform this action.
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