(i) A batch of 15 integrated-circuit chips contains 4 of an "irregular" type. If from this batch 2 chips are selected at random, and without replacement, ?nd the probability that: (a) both are "irregular"; (b) none is "irregular"; (c) only one of the two is "irregular."
(ii) If the random variable in problem (i) above was mistakenly taken to be a bi- nomial random variable (which it is not), recalculate the three probabilities and compare the corresponding results.