What is the sum of X+XX+XXX+XXXX?
Last Updated: 30.06.2025 07:45

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
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)
Valerie Mahaffey, actress in "Desperate Housewives" and "Northern Exposure," dies at 71 - CBS News
However, X +X^2 +X^3 + X^4 is a valid algebraic answer,
What is the sum of X+XX+XXX+XXXX?
1234X
What are the top AI business ideas for beginners?
and for binary would be
11010X
*Note that the abbreviation XL (for XXXX) appeared quite late in the Roman period, and never found universal favour