Question

The Roman numeral for the greatest two-digit number is
(a) IC
(b) LIL
(c) ICCCCD
(d) LXLIX

Answer 1

Hint:First of all, we need to learn how to write numbers in roman numerals. Now, find the greatest 2 digit number which is 99 and write 99 = 100 – 1. Use C for 100 and I for 1 in roman numerals.

Complete step-by-step answer:
In this question, we have to find the Roman numeral for the greatest two-digit number. First of all, let us see how to convert numbers into Roman numerals. Let us see the table for 1 to 10.

Number	Roman Number	Calculation
1	I	1
2	II	1 + 1
3	III	1 + 1 + 1
4	IV	5 – 1
5	V	5
6	VI	5 + 1
7	VII	5 + 1 + 1
8	VIII	5 + 1 + 1 + 1
9	IX	10 – 1
10	X	10

In the above table, we can write 1 as I, 5 as V, and 10 as X and write all the numbers between them by using these numbers. We can repeat any Roman numeral/symbol for at most 3 times in any roman number like we wrote 8 as VIII but 9 as IX. Similarly, we can write XXX but not XXXX. Now, we use other roman numerals for the higher-order numbers such as 50 as L and 100 as C. We write all the numbers between 1 to 100 by the combination of all the Roman numerals we have talked about. There are other symbols for higher-order numbers.
Now, let us consider our question. Here, we have to find the Roman numeral for the greatest two-digit number. We know that the greatest number of n digits is of the form 9999…..n times. So, we get the greatest 2 digit numbers as 99. Now, we can write 99 as 100 – 1. We have already discussed that Roman numeral for 100 is C and 1 is I. So, we get,
99 = 100 – 1
99 = C – I
Now, we know that in Roman numeral, when we add, we write smaller symbols on the right side while when we subtract, we write it on the left side.
For example, 10 + 1 = XI and 10 – 1 = IX.
By using this, we get, 99 = C – I = IC
Hence, option (a) is the right answer.

Note: In these types of questions, first of all, students must remember the various symbols used in Roman numerals at least from 1 to 100, and their rules. In this system, students often make mistakes by repeating the same symbol more than three times like writing 9 as VIIII instead of IX which is wrong. So this must be taken care of.