speed of boat in still water ---> x km/h
time to go 25km upstream = 25/(x-3)
time to go 35 km downstream = 35/(x+3)
but those two times are supposed to be equal, so ..
25/(x-3) = 35/(x+3)
cross-multiply, then solve for x
The speed of a stream is 3 km/h. A boat travels 25 km upstream in the same time it takes to travel 35 km downstream. What is the speed of the boat in still water?
1 answer