Question

已知集合A={x|x²-3x+2=0,x∈R},B={x|0<x<5,x∈N},則滿足條件A⊆C⊆B的集合C的個(gè)數(shù)為(　　)

A．1

B．2

C．3

D．4

Answer 1

D

A={x|x²-3x+2=0,x∈R}={x|(x-1)(x-2)=0,x∈R}={1,2},而B={1,2,3,4},又∵A⊆C⊆B,∴C={1,2},{1,2,3},{1,2,4},{1,2,3,4},共4個(gè).故選D.