A man rows his boat 90 km downstream and 5` km upstream, taking 3 hours each time. Find the speed of the stream?  Choose the most appropriate option.
A) 7 kmph
B) 5 kmph
C) 2 kmph
D) 8 kmph
E) 1 kmph
Speed downstream = d/t = 90/(3)= 
<gadget id="calculator">90/(3)</gadget>
<output>30</output>
30 kmph   Speed upstream= d/t = 51/(3)= 
<gadget id="calculator">51/(3)</gadget>
<output>17</output>
17 kmph   The speed of the stream= (30 - 17)/2 = 7 kmph   7 kmphnswer:7 kmph
<result>A</result>
A man rows his boat 90 km downstream and 5` km upstream, taking 3 hours each time. Find the speed of the stream?