If a boat goes 7 km upstream in 42 minutes and the speed of the stream is 3 kmph, then the speed of the boat in still water is : Pick
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 (13-8) km/hr= 2.5kmph . 2.5 km/hrnswer 2.5 km/hr
<result>A</result>
If a boat goes 7 km upstream in 42 minutes and the speed of the stream is 3 kmph, then the speed of the boat in still water is :