Numbers 29, 30, 31, ..., 88, 89, and 90 are written on separate slips (one number on one slip) and these slips are kept in a box. If a slip is drawn from the box at random, what is the probability that the number on the drawn slip is NOT a prime number?

A box contains 'x + 4' red, 'x – 1' green and 'x – 5' blue balls. If two balls are drawn from the bag one after another without replacement, then the probability of getting one red and one green ball is equal to the probability of getting a sum equal to or more than 8 when two fair dice are rolled. Find the probability of drawing a red ball when one ball is drawn at random from the bag.

Four persons are chosen at random from a group containing 3 men, 2 women, and 4 children. The probability that exactly two of them are children is: