A boat goes 100 km downstream in 10 hours, and 75 m upstream in 15 hours. The speed of the stream is?	Choose the correct choice from the following options.
A) 8 2 1/2 kmph
B) 2 2 1/8 kmph
C) 2 2 7/2 kmph
D) 2 2 1/2 kmph
E) 2 3 1/2 kmph
100 --- 10 2 2 1/2 kmphS = 10   ? ---- 1   75 ---- 15 US = 5   ? ----- 1 S = (10 - 5)/2   = 2 2 ½ kmph   Answer: 2 2 1/2 kmph
<result>D</result>
A boat goes 100 km downstream in 10 hours, and 75 m upstream in 15 hours. The speed of the stream is?