A boat running downstream covers a distance of 16 km in 2 hours while for covering the same distance upstream, it takes 4 hours. What is the speed of the boat in still water?  Select the correct option:
A) 4 km/hr  B) 6 km/hr  C) 7 km/hr  D) 8 km/hr  E) 2 km/hr
Rate downstream =16/2= 
<gadget id="calculator">16/2</gadget>
<output>8</output>
8 kmph.   Rate upstream=16/4= 
<gadget id="calculator">16/4</gadget>
<output>4</output>
4 kmph.   Speed in still water=	1/2	(8 + 4) kmph = 6 kmph.   ANSWER:6 km/hr
<result>B</result>
A boat running downstream covers a distance of 16 km in 2 hours while for covering the same distance upstream, it takes 4 hours. What is the speed of the boat in still water?