YaKaleiMunyai7791 YaKaleiMunyai7791 29-11-2020 Mathematics contestada Each of the four sets a1, a2, a3, and a4 contains four elements. the intersection of every i of these four sets (2 < i < 4) consisters of 5 - i elements. What is a1 U a2 U a3 U a4?