Question

Which of the following is true?

• A. CXXI = 111
• B. CXLV = 145
• C. LXXIV = 66
• D. XLIX = 59

Answer 1

The correct option is B CXLV = 145

When a Roman numeral with the larger value is on the left, we add the values together and when it is on the right, we subtract the values.

Thus, CXXI = 100 + 10 + 10 + 1 = 121.

CXLV = 100 + (50 - 10) + 5
= 155 - 10
= 145

LXXIV = 50 + 10 + 10 + (5 - 1)
= 75 - 1
= 74

XLIX = (50 - 10) + (10 - 1)
= 50 + 10 - 10 - 1
= 49

Thus, CXLV = 145 is the correct answer.