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? Choose the correct option
A) 1 hr 15 min  B) 1 hr 30 min  C) 1 hr  D) 2 hr  E) 2 hr 30 min
Upstream speed = u-v;   Downstream speed=u+v;.   According to formula, s=d/t.   u-v = 2/1, and   u+v = 60/10.   On solving these equations, we get.   u=4 and v=2.   Therefore, speed of boatman = 4 km/hr.   Hence, t=d/s.   t=5/4.   We get 1hr 15min is answer.   answer:1 hr 15 min
<result>A</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?