C is a hundred. L after the C [ CL ] means 150 but, before the C [ LC ] was not used since it means 100 - 50 or 50, the same as L alone.
CLD = 160 but LCD was meaningless to a Roman.
LCD is not a valid value in Roman Numerals.
You don't normally calculate the lcd of a single number (fraction). You would normally take the lcd of two or more fractions. In that case, ONLY the denominators are relevant to find the lcd.
The number that represents ILX is Fifty-nine (Aka 59).
Iv is 4 IV is the Roman number 4. V is the Roman number 5.
Answer 5 Roman numeral v