A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water ? Answers
A) 40 minutes	B) 1 hour	C) 1 hr 15 min	D) 1 hr 30 min	E) None of these
Solution   Rate downstream =(1/60x60) km/hr = 6 km/hr, Rate upstream = 2 km/hr.   Speed in still water =1/2(6+2) km/hr = 4 km/hr.   ∴ Required time = (5/4)hrs = 1 1/4hrs = 1 hr 15 min. Answer 1 hr 15 min
<result>C</result>
A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water ?