Java 1.8 stream, serialization, deserialization, singleton, immutable, request and prototype difference

You are given 8 identical looking balls. One of them is heavier than the rest of the 7 (all the others weigh exactly the same). You a provided with a simple mechanical balance and you are restricted to only 2 uses. Find the heavier ball.

After i wrote a program, again waiting for some time to show that to a interviewer who was busy with another candidate. Finally i shown program but he could not understand and asked me to write it again , i mean what the hell, how could it be possible to write a program that too on a paper as per his vision. I told him give me a system i will write a program as per your need. Subsequently he told me to leave with the reason "We can not hire you if you can not write a program on paper". I have a experience in java more than five years and currently working as a Technical Lead and the way they behave with me is just not acceptable. Atleast looking at my current designation (On Resume) he should have asked me some more questions. In-fact writing a program on paper is not a real evaluation, he just want me to reject with this or some other reason.