Amazon Manager - Operations interview questions

I only attended 2 rounds , out of the overall 4 rounds. The first round was Process or operations round and the second round was HR Operations round was good and all questions were related to know your process knowledge along with some analytical questions were asked like if you have 9 balls and one is lighter one how would you identify the lightest I cleared this interview second round was HR and it was good and relevant to the role however I could not clear it