The circumference of the circle with center o is divided into 12 equal arcs, marked the letters a through l as seen below. what is the number of degrees in the sum of the angles x and y?

A. 75  B. 80  C. 90  D. 120  E. 150
For this problem, it is useful to know that the measure of an inscribed angle is half the measure of its corresponding central angle. Since each unit arc is  of the circle's circumference, each unit central angle measures.
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Graph a should be your answer

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