题目

等比数列{an}中,a2=4,a5=32,则{an}的前4项和为(    )A.8                  B.16                    C.30                  D.32 答案：解析:a2=4,a5=32,数列为等比数列.q=2,a1=2,a==4,a3=8,a4=16.∴S4=30,故选C.答案:C

查看本题答案和解析