Answer to Question #223217 in Management for Kundan Singh

Question

A departmental store in works has 10 machines which may need adjustment from time to time during the day. Three of these machines are old, each having a probability of 1/11 of needing adjustment during the day, and 7 are new, having corresponding probability if 1/21. Assuming that no machines needs adjustments twice on the same day, determine the probabilities that on a particular day
i) just two old and no new machine needs adjustment
ii) If just two machines need adjustment, they are of the same type.

Answer 1

Supposing that no machine that requires modifications twice on the same day, work out the probabilities that on a precise day.

(i) just 2 old and no new machines need adjustment.

(ii) if just 2 machines need adjustment, they are of the same type.

[Ans. 0.016;0.028]