按规侓填数(1)(),2,3,6,5,10,7,();(2)40,20,(),5;(3) 1,2,4,5,7,8,10,(),().
问题描述:
按规侓填数
(1)(),2,3,6,5,10,7,();
(2)40,20,(),5;
(3) 1,2,4,5,7,8,10,(),().
答
(1)(1),2,3,6,5,10,7,(14);
(2)40,20,(10),5;
(3) 1,2,4,5,7,8,10,(11),(13).
答
1. 1 14
2.10
3.11 13
答
(1)每两个为一组,后者是前者的二倍,故填(1) (14)
(2)等比数列,公比为0.5,故填(10)
(3)奇数次项成公差为3的等差数列,偶数次项亦是如此,故填(11) (13)