Question

The roman numeral for the greatest two - digit number is:
(a) IC
(B) LIL
(C) ICCCCD
(D) XCIX

Answer 1

Hint: Firstly, we have to find the greatest two – digit number since we have to convert the greatest two – digit number into roman numeral. To convert a number to a roman numeral, we have some rules which have to be followed. Using these rules, we can convert any number to a roman numeral.

Complete step-by-step answer:
Before proceeding with the question, we must know the concept that will be required to solve this question.
To convert a number to a roman numeral, we have some rules which are as follows,
1) In roman numerals, I = 1, X = 10 and C = 100.
2) If we write any of the letters mentioned in rule 1 multiple times, we have to add the value for the same number of times. For example, II = 1 + 1 = 2.
3) No letter i.e. I, X, C can be repeated for more than 3 times.
4) In roman numerals, V = 5, L = 50, D = 500, M = 1000. V, L and D, are never repeated.
5) When a digit of lower value is written to the right of a digit of higher value, the values of the digits are added. For example, XI = 10 + 1 = 11.
6) When a lower value digit is written to the left of the higher value digit, its value is subtracted from the value of higher value digit. For example, IX = 10 – 1 = 9.
7) If we have a number greater than 10, then we will first write it in the groups of 10 and then we will use number 1 or 5.
In this question, the highest two - digit number is 99.
Using rule 7, we can write 99 as 90 + 9.
According to rule 6, we can write 90 = 100 – 10 = XC.
Also, using rule 6, we can write 9 = 10 – 1 = IX.
Using rule 5, we can write 99 = 90 + 9 = XCIX.
Hence, the answer is XCIX i.e. option (D).

Note: There is a possibility that one may think 99 as 100 – 1 and may write its roman value as IC. But according to the rule 7, we have to write a number which is greater than 10 in the form of 10n + 1 and not 10n – 1 where n is any integer.