题目

在等差数列{an}中，a1+a5=16，则a3等于（　　）                                                   A．8                                  B．4                                  C．﹣4                              D．﹣8 答案：A【分析】利用等差数列的性质2a3=a1+a5，根据已知中等差数列{an}中，a1+a5=16，代入即可得到a3的值．                    【解答】解：∵数列{an}为等差数列                                                                       ∴2a3=a1+a5=16，                                                                                                 ∴a3=8                                                                                                                 故选A                                                                                                                 【点评】本题考查的知识点是等差数列的性质，其中等差数列最重要的性质：当m+n=p+q时，am+an=ap+aq，是解答本题的关键．                                                                                                                 　                                                                                                                       

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