Answer:
263.1 is exactly three half-life, so the remaining portion is (1/2 x 1/2 x 1/2) of the original sample. That's 1/8 which is 12.5%
1) The history of egypt is still unclear; artifacts, how the pyramids were built, gods and whatnot.
2) Egypt's history being uncovered in regards to curses and amulets is still being practiced in the country and some others because of the great influence it had.
3) Egyptians being able to construct such grand structures that still stand (pyramids) serves as evidence that proves Egypt was a very advanced civilization at the peak of their advancement.
