Question

a steamer goes downstream frm one city to another in 15 hours,come back upstream in 20 hours.if the speed of water is 3 km\hr.find the distance be tween the 2 cities

Answer 1

Let speed of streamer be x km/hr
Therefore,
=> speed downstream = (x+3) km/hr
=> speed upstream = (x-3) km/hr

Distance = Speed * Time
Assuming distance between the two cities is y km,
=> Downstream, y = (x+3)*15
=> Upstream, y = (x-3)*20

=> (x-3)*20 = (x+3)*15
=> 20x-60 = 15x+45
=> 5x = 105
=> x = 21 km/hr

Therefore, distance y = (21-3)*20 = 360 km