Roman numerals question: Please put the numbers XXI to XXX in the correct order. Given numbers: XXI, XXII, XXX, XXV, XVI, XXIII, XXVIII, XXIX, XXIV, XXVII.
The correct answer is: XVI, XXI, XXII, XXIII, XXIV, XXV, XXVII, XXVIII, XXIX, XXX. This is correct because the symbols are Roman numerals, and each one must be read by its value before arranging them from smallest to largest. In the group xxv xxviii xxix xxvii xxiv xxv, XXIV comes before XXV, then XXVII, XXVIII, and XXIX.
Why the correct order is accurate
Roman numerals use letters to stand for numbers, so the first step is to translate each item into ordinary numbers. X means 10, V means 5, and I means 1. When the same or smaller symbols come after a larger symbol, we usually add them: XXI is 10 + 10 + 1 = 21.
The values are: XVI = 16, XXI = 21, XXII = 22, XXIII = 23, XXIV = 24, XXV = 25, XXVII = 27, XXVIII = 28, XXIX = 29, and XXX = 30. Arranged from smallest to largest, they become XVI, XXI, XXII, XXIII, XXIV, XXV, XXVII, XXVIII, XXIX, XXX.
A small detail matters here: the instruction says “XXI to XXX,” which suggests 21 to 30, but the given list also includes XVI, which equals 16. Since XVI is part of the given numbers, it must be placed first in ascending order.
Why the other possible arrangements are not correct
An arrangement is wrong if it places a larger Roman numeral before a smaller one. For example, XXX cannot appear near the beginning because XXX equals 30, the largest value in the list.
The easiest confusion is between XXIV, XXV, XXVII, XXVIII, and XXIX. These all start with XX, meaning 20, so the final symbols decide the order. XXIV equals 24 because I before V means “one less than five.” XXV equals 25. XXVII equals 27, XXVIII equals 28, and XXIX equals 29 because I before X means “one less than ten.”
Another point: XXVI, which equals 26, is missing from the given list. That is why the correct sequence jumps from XXV to XXVII. A correct answer should order only the numbers provided, not add missing Roman numerals.
Quick way to recognize similar Roman numeral questions
For xxv xxviii xxix xxvii xxiv xxv and similar sets, convert each Roman numeral into a normal number first, then sort the normal numbers. This avoids guessing from the letters alone.
Use this shortcut: XX means 20, then read the ending. IV = 4, V = 5, VII = 7, VIII = 8, IX = 9, and X = 10. So XXIV, XXV, XXVII, XXVIII, XXIX, and XXX are 24, 25, 27, 28, 29, and 30. Once you see the ordinary numbers, the order becomes clear.
