A boat goes 100 km downstream in 10 hours, and 75 m upstream in 15 hours. The speed of the stream is? Select:
A) 7 km/h
B) 5 km/h
C) 3 km/h
D) 2 (1/2) km/h
E) None
100 --- 10 2 (1/2) km/hS = 10   ? ---- 1   75 ---- 15 US = 5   ? ----- 1 S = (10 - 5)/2   = 2 2 ½ kmph   ANSWER:2 (1/2) 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?