Question

Some electronic devices are better used than new: the failure rate is higher when they are new than when they are six months old. For example, half of the personal music players of a particular brand have a flaw. Of the player has the flaw, it dies in the first two months with a probability of 30%, in the first four months with a probability of 70%, and in the first six months with a probability of 100%. If the player DOES NOT have the flaw, however, it dies in the first two months with a probability of 0%, in the first four months with a probability of 5%, and in the first six months with a probability of 10%.
The probability that it has the flaw is ____.

Answer 1

Given that half of the personal music players sold by a particular brand have a flaw. If the player has the​ flaw, it dies in the first six months. If it does not have this​ flaw, then only 20​% fail in the first six months.
Let A be the event that it fails in I 6 months
B1 = it has a flaw
B2 = it does not have a flaw
B1 and B2 are mutually exclusive and exhaustive
the chances that it has this​ flaw
=The probability that it has the flaw is