2 probability questions

1. Ken shoots a target with an accuracy of 0.8. If Ken decides to continue shooting until the target is hitted by a total of three times, calculate the probability that at most 5 shoots are needed.

2.All new microwaves produced by Company A are required to complete a safety test and a heat test. Records show that 4% of new microwaves will fail both tests. 90% of new microwaves will pass the safety test. Among those new microwaves which passed the safety test, 10% of them will fail the heat
test. Let S be the event that a new microwave will pass the safety test. Let H be the event that a new microwave will pass the heat test. Calculate the probability of failing the safety test given that a randomly selected new microwave has passed the heat test.
(Is this question's answer 0.02?)