A bag contains x black marbles, x + 10 white marbles, and x + 20 yellow marbles. The probability of drawing one white marble randomly is 16 more than the probability of drawing one black marble randomly. Quantity I: Total number of yellow marbles in the bag. Quantity II: 40 Establish the correct relation between Quantity I and Quantity II.

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: