Correctness of tenses in differing situations

Hi. Please tell me if the tenses are correct. Thank you in advance.

1. (talks about what he saw)
He went into a room. People were talking and getting to know each other. He then went into another room.
People were basically doing the same there too.

2. (talks about something that is factual and procceds to ask a detail question right after)
Let say there is a balloon. If you poke at it with a sharp object, it bursts open. Let me ask you a question.
How did it blow up? (answers) Yes... it blew up when you poked a sharp object at it.