1,915
The Roman numeral MCMXV represents the number 1915
1900 is shown by a thousand plus a thousand minus 100. The depiction would be MCMXV.
MCMXV - MMVII
1915 = MCMXV
You have already given it in Roman numerals
In Roman numerals, MMMD is MMMD. In Hindu-Arabic numerals, it is 3500.
They are meaningless because they are an invalid arrangement of Roman numerals
Under today's rules the Roman numerals CMXLVII represent 947.
It is nothing. That is not a roman numeral!
365
1907
48