What is the sum of X+XX+XXX+XXXX?
Last Updated: 17.06.2025 10:29

It’s a matter of interpretation.
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?
and for binary would be
1234X
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)
How do Flat Earthers explain time zones?
11010X
*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,