What is the Hindu Arabic of CDXIX?

Answer 1

D = 500

C = 100

X = 10

I = 1

Roman numerals are place-sensitive. When a Roman numeral precedes a numeral of higher value it is considered as a negative value.

So putting a value on each of the numerals we get

C = -100

D = 500

X = 10

I = -1

X = 10

and adding those together we get 419