Final answer:
To solve for the speed of the stream, we use the motorboat's speed in still water and the time difference for traveling upstream and downstream. By setting up an equation relating these quantities and solving for the speed of the stream, we can find the answer.
Step-by-step explanation:
The question asks for the speed of the stream when a motorboat travels 440 km upstream and downstream at different times. Using the boat's speed in still water and the time difference, we can set up the following equations to find the speed of the stream. Let's denote the speed of the stream as Vs and the speed of the motorboat in still water as Vb, which is 18 km/h.
The upstream speed will be Vb - Vs and the downstream speed will be Vb + Vs. Given that it takes 1 hour more to go upstream, the following equation represents the time to travel 220 km upstream and downstream respectively:
Upstream: ∀\(\frac{220}{Vb - Vs} = \frac{220}{Vb + Vs} + 1\)
Plugging in the value of Vb, we get ∀\(\frac{220}{18 - Vs} = \frac{220}{18 + Vs} + 1\)
By solving the equation, we find Vs, the speed of the stream.