The speed of a motor boat itself is 20 km/h and the rate of flow of the river is 4 km/h. Moving with the stream the boat went 120 km. What distance will the boat cover during the same time going against the stream?
Select the correct option
A) 60 km
B) 85 km
C) 70 km
D) 80 km
E) 90 km
distance=speed*time;   120=(20+4)*t;   t=5 hrs;   80 km=(20-4)*5;   80 km=80 km   ANSWER:80 km
<result>D</result>
The speed of a motor boat itself is 20 km/h and the rate of flow of the river is 4 km/h. Moving with the stream the boat went 120 km. What distance will the boat cover during the same time going against the stream?