A boat goes 100 km downstream in 10 hours, and 30 m upstream in 15 hours. The speed of the stream is?	Choose the correct choice from the following choices:
A) 22 1/7  B) 22 1/4  C) 22 1/2  D) 4  E) 22 1/3
100 --- 10 4S = 10   ? ---- 1   30 ---- 15 US = 2   ? ----- 1 S = (10 - 2)/2= 
<gadget id="calculator">(10 - 2)/2</gadget>
<output>4</output>
4 kmp Answer: 4
<result>D</result>
A boat goes 100 km downstream in 10 hours, and 30 m upstream in 15 hours. The speed of the stream is?