What is 15 in roman numerals?

In Roman numerals, the number 15 is represented as "XV".

The number 15 is formed by combining the symbols for 10 (X) and 5 (V). The symbol X represents ten, while V represents 5. When a smaller numeral appears to the left of a larger one, it is subtracted from the larger numeral. Therefore, the numeral for 10 (X) appears before the numeral for 5 (V), indicating that 10 is subtracted from 5 to give a result of 15.

It is important to note that in Roman numerals, the value of the same numeral can be added to itself up to three times. Beyond that, a subtraction rule applies. For example, three V's (VVV) would be written as "X", meaning 5 (V) is added to 5 (V), resulting in 10 (X).

Roman numerals were widely used in ancient Rome, but today they are still occasionally used for decorative purposes, for numbering certain chapters or parts in books, or for indicating dates on buildings or monuments.