 Solution

ID: past-exam-of-the-year-1-of-the-computer-science-course-of-the-university-of-oxford/2016/discrete-mathematics-continuous-mathematics-and-probability-resit/1/d/ii/solution

For each

c \in C

a \in A

such that

g (f (a)) = c

. Taking

b = f (a) \in B

supplies a preimage of

c

under

g

. Thus $g$ is a surjective function.

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