A bag contains 9 red marbles, 17 white marbles, and 7 blue marbles. What is the probability of drawing at random a blue or a red marble?
A classroom has 24 boys and 10 girls, where 10 boys and 6 girls wear glasses. Calculate the probability that a randomly selected student is a girl or wears glasses.
and are independent events, where and . What is the probability that events and both occur?