The Task: During a technical control lights and brakes was controlled on randomly selected cars. 18% had errors with the lights and 12% with the brakes. 74% had both lights and brakes in order. What is the probability that:
a) The lights were in order?
b) The brakes were in order?
c) No brakes and no lights?
d) Lights, but no brakes.
My answers(d is the problem):
d) What I have scribbled so far:
p(A) = Lights = 0.88, p(B) = brakes = 0.88 $P(A \cap B) = 0.74$
$P(A \cup B) = 0.88+0.82 - 0.74 = 0.96$ At least one of the two is functioning.
The complement of that last would be both is not working; 4%.
26% that both or at least one is not working.
From there I don't see what I'm suppose to do. The book says the answer is 8% on d). I'll check back here in the morning. Good night.