A man goes 10 km against the current of the stream in 5 hr and goes 5 km along the stream in 1hour. How long will it take to go 5 km in stationary water?  Choose the correct choice from the following.
A) 1hr 30min B) 1hr 12min C) 2hr D) 2hr 15min E) 3hr
Speed up stream = 10/5= 
<gadget id="calculator">10/5</gadget>
<output>2</output>
2 km/hr   Speed down stream= 5/1= 
<gadget id="calculator">5/1</gadget>
<output>5</output>
5 km/hr   Speed in still water= 1/2(2+5) = 7/2= 
<gadget id="calculator">7/2</gadget>
<output>7/2 = around 3.5</output>
3.5 km/hr   Time taken to travel 5 km in still water is= 5/7/2 = 10/7 = 1hr 12min   Answer is 1hr 12min
<result>B</result>
A man goes 10 km against the current of the stream in 5 hr and goes 5 km along the stream in 1hour. How long will it take to go 5 km in stationary water?