What is the sum of X+XX+XXX+XXXX?
Last Updated: 01.07.2025 11:00
1234X
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)
It’s a matter of interpretation.
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However, X +X^2 +X^3 + X^4 is a valid algebraic answer,
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?
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*Note that the abbreviation XL (for XXXX) appeared quite late in the Roman period, and never found universal favour
and for binary would be
11010X
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