In this task, you are given two sets, and you need to count the number of elements at the union of two given sets. A Set is shown by two curly braces and comma-separated numbers inside, like {1, 2, 3}. Union of two given sets is the smallest set which contains all the elements of both the sets. To find the union of two given sets, A and B is a set that consists of all the elements of A and all the elements of B such that no element is repeated.

Q: Set1: '{9, 6, 17}', Set2: '{16, 8, 6, 7}'. How many elements are there in the union of Set1 and Set2 ?

A: 6
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Q: Set1: '{1, 18, 4}', Set2: '{2, 18}'. How many elements are there in the union of Set1 and Set2 ?

A: 4
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Q: Set1: '{17, 20, 15, 7}', Set2: '{19, 4, 15}'. How many elements are there in the union of Set1 and Set2 ?

A:
6
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