Which of the following numbers in Roman numerals is incorrect?

Question

Philoid · Accepted Answer

A. LXXX is correct and represents 50+30 = 80

B. LXX is correct and represents 50+20 = 70

C. LX is correct and represents 50+10 = 60

D. LLX does not represent anything, because LL is not a valid roman numeral (C is used for 100 instead of LL)

Hence, D is incorrect.