A boatman goes 3 km against the current of the stream in 3 hour and goes 1 km along the current in 30 minutes. How long will it take to go 3 km in stationary water? Choices:
A) 5 hours
B) 4 hours
C) 3 hours
D) 2 hours
E) 1 hours
Explanation:   Speed upstream = 3/3= 
<gadget id="calculator">3/3</gadget>
<output>1</output>
1 km/hr   Speed downstream= 1/(30/60)= 
<gadget id="calculator">1/(30/60)</gadget>
<output>2</output>
2 km/hr   Speed in still water= 1/2(2+1)= 3/2 km/hr   Time taken to travel 3 km in still water = 3/(3/2) = 6/3= 
<gadget id="calculator">6/3</gadget>
<output>2</output>
2 hours   Answer: Option 2 hours
<result>D</result>
A boatman goes 3 km against the current of the stream in 3 hour and goes 1 km along the current in 30 minutes. How long will it take to go 3 km in stationary water?