What is the roman numeral for 149?

Answer 1

CXLIX

C = 100, XL = 40, IX = 9

BTW, CIL doesn't work because IL is not proper. You can only do XL, not VL or IL.

The same for M (= 1000). You can write CM (900), but NOT DM, LM, XM, VM, or IM. That's why the year 1999 is written MCMXCIX and not IM.