Answer:
a. [tex] A\cap B=\{6, 11\}[/tex]
Step-by-step explanation:
U = {3, 4, 6, 7, 9, 11, 12, 15}
A = {3, 6, 11, 12}
B = {6, 7, 11, 15}
Since, 6 and 11 are common elements in sets A and B. Therefore ,
[tex] A\cap B=\{6, 11\}[/tex]
