Good explanations thanks

A man has 10 keys on a key ring, one of which opens the door to his apartment. Having had one too many drinks, he returns home to find himself unable to distinguish between the keys. Instead, he chooses a key at random and tries it. If the key fails to open the door, he will discard it and choose at random one of the remaining keys, until he is able to get in. i. Is this a binomial experiment? Why or why not? Be thorough. ii. What is the probability that he must wait until the fifth key selected in order to gain entry? Define your notation and show your work