>>>>>Hi everybody,
>>>>>
>>>>>This is a puzzle, which could be asked on a interview. I could not find a best answer.
>>>>>
>>>>>There is a 100 floor building. You have two glass balls. You need to find out the floor number, starting from which these balls will broke by minimal number of steps.
>>>>>
>>>>
>>>>What is definition of a step in this case?
>>>
>>>I think, one dropping of a ball is a step.
>>
>>Are you saying that I need to find out the lowest floor of this building where a glass ball will break when dropped and I need to explain how it could be determined in the least number of actions?
>>
>>Renoir
>
>Yes, exactly. Thanks for translating this problem into proper English for me :)

Go to floors:
14
27
39
50
60
69
< and so on, going adding 1 less floor each time >
99

If ball breaks at any floor, go to previous step+1, and go to each floor in ascending order.

Max steps=14, occurring at at 13, 26, 38, 49, etc. I chose 14 as the starting point because the sum of n + (n - 1) + (n - 2)... series for n=14 is the lowest n that gives a result greater than 100.

I don't recall how to express this in the proper mathematical terminology...