What is the sum of X+XX+XXX+XXXX?
Last Updated: 27.06.2025 23:55

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
Meta takes $15 billion stake in Scale AI in bid to catch competitors - The Washington Post
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)
11010X
*Note that the abbreviation XL (for XXXX) appeared quite late in the Roman period, and never found universal favour
Aussie firms Soul Patts and Brickworks' $9 billion merger sends their shares rocketing - CNBC
1234X
However, X +X^2 +X^3 + X^4 is a valid algebraic answer,
It’s a matter of interpretation.