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	Choose the most appropriate option:  A) 12 kmph  B) 13 kmph  C) 14 kmph  D) 15 kmph  E) None of these
Explanation:   Rate upstream = (7/42)*60= 
<gadget id="calculator">(7/42)*60</gadget>
<output>10</output>
10 kmph.   Speed of stream= 3 kmph.   Let speed in still water is x km/hr   Then, speed upstream = (x �3) km/hr.   x-3 = 10 or x = 13 kmph   Answer: 13 kmph
<result>B</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