A man goes downstream at 13 kmph, and upstream8 kmph. The speed of the stream is
Choices:	A) 0kmph	B) 4kmph	C) 16kmph	D) 2.5kmph	E) 26kmph
Speed of the stream = 1/2(13-8)kmph   =2.5kmph.   correct option :2.5kmph
<result>D</result>
A man goes downstream at 13 kmph, and upstream8 kmph. The speed of the stream is