Answer:
0.625 = 62.5% probability that part B works for one year, given that part A works for one year.
Step-by-step explanation:
We use the conditional probability formula to solve this question. It is
In which
P(B|A) is the probability of event B happening, given that A happened.
is the probability of both A and B happening.
P(A) is the probability of A happening.
The probability that part A works for one year is 0.8 and the probability that part B works for one year is 0.6.
This means that
The probability that at least one part works for one year is 0.9.
This means that:
We also have that:
So
Calculate the probability that part B works for one year, given that part A works for one year.
0.625 = 62.5% probability that part B works for one year, given that part A works for one year.