Which of the given numbers are NOT written correctly?
a. IIX
b. XVII
c. XVV
d. XXIXX
Answer (1)
To determine which of the given Roman numerals are not correctly written, we need to understand the basic rules of Roman numeral formation. Roman numerals are formed by combining letters that represent values: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000).
Here are the basic rules for writing Roman numerals:
Repetition Rule : A numeral can be repeated up to three times to add up to its value. For example, III is 3.
Subtraction Rule : A smaller numeral in front of a larger numeral indicates subtraction. For example, IV is 4 (5 - 1).
Addition Rule : A smaller numeral after a larger numeral indicates addition. For example, VI is 6 (5 + 1).
Let's evaluate each option:
a. IIX : This is not a valid numeral. The subtraction rule only allows for smaller numerals to precede larger ones when they are just one step apart. IX (9) is valid, but IIX is not.
b. XVII : This is correct. It represents 17 (10 + 5 + 1 + 1).
c. XVV : This is not correct. The numeral V cannot be repeated.
d. XXIXX : This is incorrect. The numeral XX next to another XX before IX is invalid due to repetition exceeding allowed logic that confuses value ranking.
In conclusion, the numerals that are NOT written correctly are a. IIX, c. XVV, and d. XXIXX.
