Problema Solution
Robert has a jet ski that will travel at the rate of 35mph in still water. he can go 50miles up a river in the same amount of time it takes him to go 75miles down the river. how fast can Robert travel going down the river.
Answer provided by our tutors
still water speed = 35 mph
now,
speed of stream=x
50/(35-x)= 75/(35+x)
=> 10(35+x)=15(35-x)
=> 25x=5*35
=> x=7
thus speed of stream=7 mph
now Robert speed going down=35+7=42 mph