A boat goes 100 km downstream in 10 hours, and 75 m upstream in 15 hours. The speed of the stream is?
Select the correct option.
A) 2 (1/2) km/h	B) 4 km/h	C) 6 km/h	D) 3 km/h	E) 7 km/h
Explanation:   100 --- 10 3 km/hS = 10   ? ---- 1   75 ---- 15 US = 5   ? ----- 1 S = (10 - 5)/2   = 2 2 ½ kmph   Answer: Option 3 km/h
<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?