Questien 2 (TRAFFIetionm An engineer designed a trafic light by using three sele
ID: 3322850 • Letter: Q
Question
Questien 2 (TRAFFIetionm An engineer designed a trafic light by using three selectors: S, S, and S.He decided w us two selectoes S and S2 in series and the third selector S in parallel so that the sssem wull sill work if either selector S or both selectors S and S2 work together All the three selectes work independently, Results showed that selectors S, 82, and S worked in 70% 75 ud 65% ofcases, respectively. Traffic Signal Fig. Traffic rules are for our safety (a ) What is the chance of the signal system failing? (b ) Assume the system worked; what is the conditional probability that selector S g 9992 9988 9984 .9978 9971 902 %51 m6 .9994 .9992 .9989 .9985 m, m3 994 992 998 194 99%3Explanation / Answer
a) probability of failiing = (1- p3) *(1- p1*p2)
=(1-0.65)(1-0.7*0.75)
=0.16625
b) Given he system worked , probability that S3 functioned
= P(S3 functioned and system worked)/P(system worked)
= 0.65/(1-0.16625)
= 0.7796101