To be fair to him, that last question is a trick question. I can't stand questions like that. The ambiguity around "have" is what gives the asker the "gotcha" moment. If "have" means "at least," then all 12 months have 28 days. But if "have" refers to the exact total, it would just be February. Most of the time when people say "have" in reference to the number of days in a month in casual conversation, they are referring to the total number.
But he's gotta be able to get that first one man, come on now.