*16. Suppose n balls having weightsI mage are in an urn. These balls are sequentially removed in the following manner: At each selection, a given ball in the urn is chosen with a probability equal to its weight divided by the sum of the weights of the other balls that are still in the urn. LetI mage denote the order in which the balls are removed—thusI mage is a random permutation with weights.

(a) Give a method for simulating Image.

(b) Let be independent exponentials with rates Image.

Explain how can be utilized to simulate Image.