What is the sum of X+XX+XXX+XXXX?
Last Updated: 22.06.2025 00:25

It’s a matter of interpretation.
*Note that the abbreviation XL (for XXXX) appeared quite late in the Roman period, and never found universal favour
1234X
Trump is forcing this dirty, costly coal plant to stay open - The Washington Post
What is the sum of X+XX+XXX+XXXX?
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)
However, X +X^2 +X^3 + X^4 is a valid algebraic answer,
11010X
and for binary would be
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
Porsche Built A One-Off Street-Legal 963 Hypercar For 88-Year-Old Roger Penske - Jalopnik