在礼堂椅被安排在这样一种方式,前两排的椅子都有相同数量的行.第三和第四行各有三把椅子比第一和第二行；第五行和第六行各有三

在礼堂椅被安排在这样一种方式,前两排的椅子都有相同数量的行.第三和第四行各有三把椅子比第一和第二行；第五行和第六行各有三把椅子比第三和第四排,每排的椅子数序列形成一个等差数列.前两排各有27把椅子,和最后两排各有114把椅子.（1）一共有多少行椅子在那里（2）分别在第13行和30行有多少把椅子.
原题。
Chairs in an auditorium are arranged in rows in such a way that the first two rows each have the same number of chairs.The third and fourth rows each have three more chairs than the first and second row; the fifth and sixth rows each have three more chairs than the third and fourth row,etc.The sequence of number of chairs for every second row forms an arithmetic sequence.The first two rows each have 27 chairs,and the last two rows each have 114 chairs。