In a large city the number of supporters for the mayor is not known.

If two citizens are chosen at random, the probability of choosing one supporter and another one that opposes the incumbent mayor is 0.18.

It is known that the number of supporters for the incumbent mayor exceeds that of his opponents.

-1 Why is it important to say that the city is large?

-2 What is the proportion of supporters for the incumbent mayor?

B.

In a big city there are residents who support the incumbent mayor and others who oppose him.

If three people are randomly selected from the city, the probability of not more than two supporting the incumbent mayor is 0.992.

- What is the proportion of supporters for the incumbent mayor?