Question

Which of the following is a correct roman numeral?
A). CXL
B). CC
C). XX
D). All of the above

Answer 1

Hint: In these types of questions you should be aware of the system of Roman numerals such as the symbols which it is used to represent the systems of numerical notation use these instructions which will help you to get closer to the solution to the question.

Complete step-by-step solution -
We know that roman numerals are the system of symbols which are used to represent the number systems in ancient times .
Let’s find out how, So in the roman numerals system we use some specific symbols which are used to represent some specific numbers such as I represents 1, V represents 5, X represents 10, L represents 50, C represents 100, D represents 500 and at last M represents 1000 so there is a basic method to find the values of combinations of symbols which is if a symbol is placed after another symbols which represents equal or greater number adds the values of symbols and the symbol placed before symbol which represents the greater number value gets subtracted let’s take the roman numeral CXL to explain this method so in CXL, C represents the greater number as compare to X and L so values of C and XL will add but in case of XL, L represents the greater number as compare to X therefore the subtraction of values will take place i.e. XL = 50 – 10 = 40 since C = 100 therefore CXL will be equal to 100 + 40 i.e. 140.
So all the given options are correct roman numerals how?
Let’s talk about first option CXL so in the roman system C represents the number 100, X represents the number 10 and L represents number 50
So we can say that CXL is a roman numeral
For the second option, we already know that C represents the number 100 in roman system
Therefore CC is also a roman numeral
Since X represents the number 10 so option C i.e. XX is also a roman numeral
Since all the symbols given in the options belong to the roman system therefore all options are roman numerals
Hence, option D is the correct option.

Note: In the above question we checked if the options are roman numerals or not. The trick concept while dealing with problems of this kind is the knowledge of basic information about roman system. Only latin alphabets like (I, V, X, L, C, D and M) are used in roman system.