If a boat goes 7 km upstream in 42 minutes and the speed of the stream is 8 kmph, then the speed of the boat in still water is : Answers
A) 2.5 km/hr B) 4.2 km/hr C) 5 km/hr D) 10.5 km/hr E) None of these
Solution   Speed of stream = 1/2 (18-8) km/hr=5kmph . Answer 5 km/hr
<result>C</result>
If a boat goes 7 km upstream in 42 minutes and the speed of the stream is 8 kmph, then the speed of the boat in still water is :