What is the sum of X+XX+XXX+XXXX?
10.06.2025 08:02

*Note that the abbreviation XL (for XXXX) appeared quite late in the Roman period, and never found universal favour
However, X +X^2 +X^3 + X^4 is a valid algebraic answer,
and for binary would be
A Cosmic Tech Mystery Results in Literal Lost Souls in This Sci-Fi Short Story - Gizmodo
Given the use of upper case, I personally would initially assume Roman numerals*, so the answer would be C (100 in present-day decimal notation)
It’s a matter of interpretation.
1234X
If You Can Perform These 5 Moves at 60, Your Body’s Decades Younger - Eat This Not That
11010X
as would be assuming that these are representations of conventional numbers, in which case the answer for number bases of five or more would be
What is the sum of X+XX+XXX+XXXX?