Final answer:
The speed of the boat in still water is c m/s.
Step-by-step explanation:
To find the speed of the boat in still water, we can use the concept of relative velocity. Let's assume the speed of the boat in still water is B m/s. When the boat travels upstream against the current, its effective speed is (B - c) m/s. Similarly, when the boat travels downstream with the current, its effective speed is (B + c) m/s. Since the boat takes the same amount of time for both journeys, we can set up the following equation:
Distance/Upstream Speed = Distance/Downstream Speed
The distances cancel out, and we are left with:
(B - c) = (B + c)
Simplifying the equation, we get:
2c = 2B
Dividing both sides by 2, we find that:
c = B
Therefore, the speed of the boat in still water is c m/s.