In this task, you are given two sets, and a question. You need to find whether an element is at the intersection of two given sets.  A Set is shown by two curly braces and comma-separated numbers inside, like {1, 2, 3}. The intersection of two given sets is the largest set which contains all the elements that are common to both sets. An element is at the intersection of two given sets, A and B, if common to both A and B. Classify your answers into 'Yes' or 'No'.

Set1: '{4, 5, 6, 7, 11, 13, 17, 18}', Set2: '{3, 5, 6, 7, 9, 14, 15, 16, 17, 19}'. Is the element '15' in the intersection of Set1 and Set2 ?
No

Set1: '{2, 3, 6, 15, 16, 18}', Set2: '{6, 7, 10, 11, 17}'. Is the element '3' in the intersection of Set1 and Set2 ?
No

Set1: '{3, 6, 9, 12, 15, 16, 17, 19, 20}', Set2: '{2, 7, 9, 11, 13, 15, 16, 18, 19}'. Is the element '7' in the intersection of Set1 and Set2 ?

No