In this exercise, we consider a set of 200 people.Among these, 40
are retired(call this set A), 120 are women(call this set B) and 115 use public
transport.We assume that 75 % of the retired people use public transport, that being
retired is equally likely
for men and women and that there are 65 women that use
public transport.We consider probabilities by picking a person from this group at
random.

(d).If there are 15 retired women using public transport, can you compute the
probability of picking a working man that doesn 't use public transport?



  ANSWOR:

 Sets: A = 40, B = 120, C = 115, B AND C = 65

 65 women use p.t, so 115-65= 50 men use p.t. if we assume no newfag genders. Number of men is 200-120= 80. Number of men not using public transport is thus 80-50= 30.

 30 of of the 40 retired people use p.t., and out of those 30-15= 15 are men. But there are 20 retired men in total, so out of the 30 men not using p.t., 5 are not working men. Thus, 30-5= 25 men are working and do not use p.t., meaning the probability of picking such a man is 25/200 = 12.5%
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