题目

题型：解答题难度：简单来源：不详

(6分) 如图①、图②、图③……是用围棋子摆成的一列具有一定规律的“山”字．

(5)   按图示的规律填空．

图形标号	①	②	③	④	……
围棋子的数目(颗)	7

(6)   第n个图形所对应的围棋子的数目为___________颗．
若某个图形中有围棋子142颗，它是第__________个图形．

答案

(1) 12，17，22
(2)  
(3) 28

解析

解：(1) 12，17，22···················································································· 3分
(2) ·················································································· 5分
(3) 28·························································································· 6分