ɸ(200) =A100B64C80D60Answer: C. 80 Read Explanation: ɸ(200) = ɸ(8X25)=ɸ(2³ X 5²) ɸ(2³ X 5²) = 200 (1-1/2)(1-1/5)=200 X 1/2 X 4/5 = 80Read more in App