## Thinking Mathematically (6th Edition)

$A = \{0, 1, 1, 2, 2, 2, 3, 3, 3, 3\}$ $B = \{3, 2, 1, 0\}$ a. Those sets aren't equivalent as they have a different number of elements. b. Those sets are equal because their unique elements are exactly the same ( $0, 1, 2, 3$ for both).