The meandering streams form in places that have low elevation and are flat, covered with softer sediments. The stream starts as mostly straight, but as time passes it erodes one of the banks, while depositing on the opposite bank, become very curvy, snake-like in shape, thus a meandering stream. In the meandering streams, the water has the most velocity at the outer banks. This results in greater erosion of the outer banks, and this part constantly moves outwards. In the same time, the water has the least velocity at the inner bank, resulting in deposition of the material that it has been carrying with it, so this part constantly grows inwards.
So, these are independent events, so we know we need to multiply the probability of the spinner landing on green by the probability of the spinner landing on yellow.
There is no green space, so that means the probability is 0.
