Given the sets

$$A= \{ 1, 5, 7, 10, 11 \} \quad \mbox{and} \quad B= \{ 1, 3, 7, 10 \}$$

find the following sets and write the answer using set notation. Separate multiple elements by commas. Write empty if the set contains no elements.

(a) $A \cap B =$

(b) $A \cup B =$