math
posted by Tonto on .
The speed of a boat in still water is 8 km/h. It travels 60 km upstream and 60 km downstream in a total time of 16 hours. What is the speed of the stream?

Let the speed of the stream be x km/h
Time to go upstream = 60/(8x)
time to go downstream = 60/(8+x)
so 60/(8x) + 60/(8+x) = 16
multiply both sides by (8x)(8+x), simplify and solve the resulting quadratic equation.