A) 14 km/hr
B) 12 km/hr
C) 10 km/hr
D) 16 km/hr
E) 18 km/hr
Correct Answer: D
Solution :
Rate downstream \[=\frac{77}{7}\times 2\] \[\text{= 22 km/hr}\] Time taken in upstream jouney \[\text{=}\frac{7}{2}\times 2.2=7.7\] hours Rate upstream \[=\frac{77}{7.7}=10km/hr\] \[\therefore \] Speed of boat in still water \[=\frac{1}{2}(22+10)=\frac{1}{2}\times 32=16km/hr\]You need to login to perform this action.
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