Gartner Research Associate interview questions

I was given the data test to finish at home, then I was brought on site, the head of the team decided to join the first round instead, she was supposed to be on the second. She asked many unrelated questions and seems never really talked about the role I was applying. The entire experience wasn't great. And the reject letter was sent 20 mins after the on site interview, probably the most efficient HR that I ever encountered.