24. ZABC and ZDEF are linear pairs. Which of the following is true?

a. If m ABC = 2m DEF, then m ABC = 120 and m DEF = 60.

b. If m ABC = m DEF + 40, then m ABC = 140 and m DEF = 40.

c. If m ABC = m DEF - 30, then m ABC = 30 and m DEF = 150.

d. If m ABC = 3m DEF, then m ABC = 130 and m DEF = 60.
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