Questions about math problems?

1) A teacher found that her class of 25 students had 9 who spoke English, 6 who spoke only Spanish, 4 who spoke only Russian, 2 who spoke only Vietnamese, and 4 who spoke only Hmong. Find the probability that in a group of 5 chosen at random, at least two spoke Vietnamese or Hmong.

2) 11.3% of the population is 65 or older. Find the probability that the following number of persons selected at random from 50 people are 65 or older. The probability that all are 65 or older is _____.

3) 90% of the voters favor Ms.Stein. If 2 voters are chosen at random, find the probability that none support Ms.Stein, and the probability that at least one support Ms.Stein.

I've been working on these problems for a week and still can't figure out, so any help is appreciated. Thanks!