What is the sum of X+XX+XXX+XXXX?

Last Updated: 03.07.2025 00:06

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)

and for binary would be

1234X

What made you recently say to yourself, “Wait. Really?”

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

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

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However, X +X^2 +X^3 + X^4 is a valid algebraic answer,

11010X

What is the sum of X+XX+XXX+XXXX?

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