If a boat is rowed downstream for 500 km in 5 hours and upstream for 240 km in 6 hours, what is the speed of the boat and the river? Select:
A) 70 , 30
B) 30 , 70
C) 70 , 70
D) 30 , 30
E) 80 , 50
Explanation:   If x: speed of boats man in still water   y: speed of the river   Downstream speed (Ds) = x + y   Upstream speed (Us) = x â€“ y   x = (Ds + Us) / 2   y = (Ds â€“ Us) / 2   In the above problem Ds = 100 ; Us = 40   x = (100 + 40) / 2 = 140/2= 
<gadget id="calculator">140/2</gadget>
<output>70</output>
70 km/hr   y= (100 - 40)/2 = 60/2= 
<gadget id="calculator">60/2</gadget>
<output>30</output>
30 km/hr   70 , 30NSWER: 70 , 30
<result>A</result>
If a boat is rowed downstream for 500 km in 5 hours and upstream for 240 km in 6 hours, what is the speed of the boat and the river?