SOLUTION: sailor raju covered a distance of 8km in 1hr and 40 minutes down stream and returns to the starting point.If the speed of the stream is 2km/hr,find the speed of the boat in still w

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: sailor raju covered a distance of 8km in 1hr and 40 minutes down stream and returns to the starting point.If the speed of the stream is 2km/hr,find the speed of the boat in still w      Log On


   

Question 685702: sailor raju covered a distance of 8km in 1hr and 40 minutes down stream and returns to the starting point.If the speed of the stream is 2km/hr,find the speed of the boat in still water.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let the speed of boat in still water be x km/h
with current speed = (x+2) km/h
he covered a distance of 8 km
time 1 h 40 m= 1 2/3 hours = 5/3 hours
time = distance /speed
5%2F3+=+8%2F%28x%2B2%29
cross multiply
5(x+2)=8*3
5x+10=24
5x=24-10
5x=14
x=14/5
x=2.8 km/h speed of boat in still water.