1.(2010·新课标全国卷)已知集合A={x||x|≤2,x∈R},B={x|≤4,x∈Z}
则A∩B= ( )
A.(0,2) B.[0,2] C.{0,2} D.{0,1,2}
解析:A={x|-2≤x≤2},
B={x|0≤x≤16,x∈Z},
故A∩B={0,1,2}.
答案:D
2.设集合A={4,5,7,9},B={3,4,7,8,9},全集U=A∪B,则集合∁U(A ∩B)中的元素共有 ( )
A.3个 B.4个 C.5个 D.6个
解析:∵A={4,5,7,9},B={3,4,7,8,9},
∴A∪B={3,4,5,7,8,9},A∩B={4,7,9},
∴∁U(A∩B)={3,5,8},
∴∁U(A∩B)共有3个元素.故选A.
答案:A