A boat goes 24 km upstream and 36 km downstream total time taken is 6 hours. If the boat goes 36 km upstream and 24 km downstream then the time taken is 6 1/2 hours. Find the speed of boat in still water?
(a) 9 km/hr
(b) 8 km/hr
(c) 12 km/hr
(d) 10 km/hr
Sol:
Subtracting both we get 60 km downstream at 5 hours
Speed of downstream = 12 km/hr
From 1 ⇒ for 36 km downstream = 3 hour
24 km upstream in 3 hours
Upstream = 8 km/hr
Speed of boat = 10 km/h