I have been set a few examples to work throught and ive had a go at them im just wondering if you could help me double check them as im not entirely happy.
An electronic assembly consists of two subsystems, A and B, say. After manufactureeach assembly is tested
P(A is faulty) = 0.04
P(B is faulty but A is not faulty) = 0.01
P(Both A & B are faulty) = 0.025
question1 : Calculate P(A is faulty but B is not)
my answer: 0.04 - 0.025 = 0.015
Question2 : Calculate P(B is faulty)
my answer : 0.01 + 0.025 = 0.035
Question3 : Do faults in the two subsystems occur independantly?
my answer: The two subsystems are independant as they are do not effect the other.
Question4: Calculate (A is Faulty Given That B Is Faulty)
my answer: 0.04 + 0.015 - 0.04 x 0.015 = 0.0544
So i know the last one is almost definately wrong and is there any way to mathematically determine that the two subsystems are independant of each other.
Any help is appreciated.