A sailor goes 10 km down stream in one hour and returns in 1 hour 40 minutes. Find the speed of the sailor in still water and speed of the current.
FYI: It's Linear Equation
Answers
Answer:
Speed of ship in still water = 38.8536585366 km/h = 38.9 km/h
Step-by-step explanation:
the ship goes 10km downstream in 1 hour
speed of the stream downstream = d/t = 10 km/h
1 hour and 40 minutes = 1.66667 hours.
Lets round up 1.66667 hours
Therefore,
1 hour and 40 minutes = 1.7 hours
distance upstream = speed / time = 10/1.7 = 5.9km
∴ speed of the stream upstream = d × t = 5.9 × 1.7 = 10.03 km/h
Let the speed of the ship in still water be x
Relative speed between water stream and ship in upstream = (x-10.03) km/h
Relative speed between water stream and ship in downstream=
(x+10) km/h
Time taken to travel 5.9km upstream = 10/(x-10.03) hours
Time taken to travel 10km downstream = 10/(x+10) hours
A.T.P (According to the Problem)
10/(x+10) = 5.9/(x-10.03)
or, 10(x-10.03) = 5.9(x+10)
or, 10x - 100.3 = 5.9x + 59
or, 4.1x = 159.3
or, x = 38.9 km/h