What is the sum of X+XX+XXX+XXXX?
Last Updated: 23.06.2025 18:58

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)
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
11010X
Life from oceans to savannas explained with one single rule - Phys.org
1234X
and for binary would be
It’s a matter of interpretation.
Nvidia CEO sends blunt 7-word message on quantum computing - TheStreet
What is the sum of X+XX+XXX+XXXX?
*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,
Confirmed rabies case in Fayetteville after fox bites home inspector - WRAL.com