Question 70

Speed of a boat is 8 km/hr in still water and the speed of the stream is 2 km/hr. If the boat takes 8 hours to go to a place and come back, then what is the distance (in km) of the place?

Solution

Speed of boat in still water = 8 km/hr and speed of stream = 2 km/hr

Let distance covered = $$d$$ km

According to ques,

=> $$\frac{d}{(8-2)}+\frac{d}{(8+2)}=8$$

=> $$\frac{d}{6}+\frac{d}{10}=8$$

=> $$\frac{10d+6d}{60}=8$$

=> $$\frac{4d}{15}=8$$

=> $$d=\frac{15\times8}{4}=30$$ km

=> Ans - (B)

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