A signal which can be green or red with probability 45

A signal which can be green or red with probability 4/5 or 1/5 respectively,is received by station A and transmitted to station B,the probablity of each station receiving the signal coreectly is 3/4.if hte signal received at station B is green,then the probabilty of original signal was red is?

Solution

Green and correct 4/5 *3/4= 12/20

Green and incorrect 4/5 *1/4= 4/20

Red and correct 1/5 *3/4= 3/30

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