As we all know, snowstorms frequently last more than one day, sometimes 2, sometimes 3. This means that probability of snowing Monday is not independent from the probability of snowing the next day (a Tuesday).
Assuming in Neverland,
the snowstorms only last one day, and
the probability of snowing is completely INDEPENDENT from one day to another, then we can use the multiplication rule
Probability of snowing Monday AND Tuesday
=Probability of snowing Monday * Probability of snowing Tuesday
=P(Monday)*P(Tuesday)
=(1/3)*(1/3)
=1/9 (Only in Neverland!)
