Apparently i cleared the three rounds of the interview, and was asked to attend the fourth round (telephonic) with the cofounder. After some intro, he asked me two math problems, which i was unable to answer. Interview ended there. This feels weird because in the last three years, i have never been asked a math problem in an interview. And that too in the final round? I have a feeling they already hired someone else and was looking for a way to reject me? Feels shitty anyway. Thoughts?