A river boat can travel at $20$ km per hour in still water. The boat travels $30$ km upstream against the current
then turns around and travels the same distance back with the current. If the total trip took $7.5$ hours,
what is the speed of the current? Solve this question algebraically as well as graphically.
[Math] River boat round trip
algebra-precalculus
Best Answer
Hint: if the current is $c$, the speed upstream is $20-c$ and downstream is $20+c$