The speed of a boat in still water is 24 kmph. What is the speed of the stream if the boat can cover 64 km downstream or 32 km upstream in the same time?  Options:
A) 8 kmph  B) 6 kmph  C) 7 kmph  D) 5 kmph  E) 4 kmph
X = the speed of the stream   (24 + X) / (24 - X) = 2/1   24+ X = 48 - 2X   3X = 24   X = 8 km/hour   If the speed of the stream is 8km/hour, then the 'downstream' speed of the boat is   24+8= 
<gadget id="calculator">  24+8</gadget>
<output>32</output>
32km/hour and the 'upstream' speed of the boat is 24-8= 
<gadget id="calculator">24-8</gadget>
<output>16</output>
16km/hour. In that way, if the boat traveled for 2 hours, it would travel 2x32= 64km downstream and 2x16 = 32km/hour upstream.   8 kmphnswer : 8 kmph
<result>A</result>
The speed of a boat in still water is 24 kmph. What is the speed of the stream if the boat can cover 64 km downstream or 32 km upstream in the same time?