Suppose each point and letter in the figure represents a child on a playground, and an arr...

Suppose each point and letter in the figure represents a child on a playground, and an arrow going from I to J means that I is the sister of J.

a. Based on the information in the figure, who are definitely girls and who are definitely boys?

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b. Suppose we write “A is the sister of B” as an ordered pair (A,B). Based on the information in the diagram, write the set of all such ordered pairs.

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c. Is the set of all ordered pairs in (b) a function with the domain equal to the set of all first components of the ordered pairs and with the range equal to the set of all second components?