You should use Bayes' Rule. Therefore, the answer is 1/2.
Need some help with this problem:
A nurse is to give Mr. Sean a pill each day. The probability that the nurse forgets to administer the pill is 2/3. If he receives the pill, the probability that Mr. Sean will die is 1/3. If he does not get the pill, the probability that he will die is 3/4. Mr. Sean died. What is the probability that the nurse did not forget to give Mr. Sean the pill? What is the probability that Mr. Sean died and the nurse did not give him the pill?
By saying use Bayes Theorem and then saying the answer is 1/2, your original reply implied that the answer to the first question is 1/2, which is wrong.