已知等差数列共有10项,其中奇数项之和15,偶数项之和为30,则其公

已知等差数列共有10项,其中奇数项之和15,偶数项之和为30,则其公差是【     】.

A.5             B.4        C. 3          D.2

答案

C


解析:

,故选C.

相关题目

进当铺的男孩 毕淑敏 儿子有一天对我说,他们班同学有一支
进当铺的男孩 毕淑敏 儿子有一天对我说,他们班同学有一支派克笔要出让,开价人民币100元整。 “这笔是什么来路,不会是赃物吧” 我说。 儿子说笔
下列关于科学家与其在物理学上的重大发现,对应正确的是A
下列关于科学家与其在物理学上的重大发现,对应正确的是A.奥斯特——电磁感应现象           B.  麦克斯韦——证实电磁波存在C.查德威克
---Who         the men's 100-metre hurdle race? ---Of course Liu Xiang
---Who         the men's 100-metre hurdle race? ---Of course Liu Xiang.He         others. A.won, won        B.beat, beat            C.beat, won      
下列说法正确的是:A.Li是最活泼金属,F是最活泼非金属   
下列说法正确的是:A.Li是最活泼金属,F是最活泼非金属     B.Mg(OH)2碱性比Ca(OH)2强C.元素周期表有7个主族,7个副族,1个0族,1个Ⅷ族,共16纵行D.
When I was six, Dad brought home a dog one day, who was called “Brownie”. M
When I was six, Dad brought home a dog one day, who was called “Brownie”. My brothers and I all loved Brownie and did different things with her. One of us would walk her, another would feed her
 ---With the country’s pension fund gap becoming wider than ever, retirement
 ---With the country’s pension fund gap becoming wider than ever, retirement age should be postponed immediately. ---Easier said than done.          we take all factors into account, w
(本小题满分15分)w*w^w.k&s#5@u.c~o*m  如图,某单位用木料
(本小题满分15分)w*w^w.k&s#5@u.c~o*m  如图,某单位用木料制作如图所示的框架,框架的下部是边长分别为    (单位:米)的矩形,上部是斜边长为的等腰
向0.1 mol·L-1的CH3COOH溶液中加入CH3COONa晶体或加水稀释时,均
向0.1 mol·L-1的CH3COOH溶液中加入CH3COONa晶体或加水稀释时,均会引起(  )A.溶液的pH都增加                     B.CH3COOH电离程度增大C.溶

最新题目