255.

The X effect is the observation that warmer water sometimes freezes faster than colder water. Although the observation has been verified, there is no single scientific explanation for the effect.

The effect is named for Tanzanian X. He first encountered the phenomenon in 1963 in Form 3 of Magamba Secondary School, Tanganyika when freezing ice cream mix that was hot in cookery classes and noticing that they froze before cold mixes. After passing his O-level examinations, he became a student at Mkwawa Secondary (formerly High) School, Iringa, Tanzania. The headmaster invited Dr. Denis G. Osborne from the University College in Dar Es Salaam to give a lecture on physics. After the lecture, X asked him the question "If you take two similar containers with equal volumes of water, one at 35 °C (95 °F) and the other at 100 °C (212 °F), and put them into a freezer, the one that started at 100 °C (212 °F) freezes first. Why?" only to be ridiculed by his classmates and teacher. After initial consternation, Dr. Osborne experimented on the issue back at his workplace and confirmed X's finding. They published the results together in 1969.

Solve for X