Procter & Gamble Process and Engineer interview questions

I was only informed of the location and the time 1 day before the interview. They changed the interview time various times in just 1 day and the email announcement is not formal at all. The interview took about 1 hour and I was asked what is my improvement/invention for my Chemical Engineering Major or Heat Transfer subject and I don’t think it is a good question because what did the interviewer expect from the student??? (Expect student to invent new things like a professional researchers)