In a certain conference room each row of chairs has the same number of chairs, and the number of rows is 1 less than the number of chairs in a row, How many chairs are in a row?
(1) There is a total of 72 chairs
(2)After 1 chair is removed from the last row, there is a total of 17 chairs in the last 2 rows.
the number of rows is 1 less than the number of chairs in a row 是说,如果每排有N个椅子,那么一共有 N-1 排.那么椅子的总数就是N(N-1)=72 条件1成立. 条件2:最后一排移走一个后,最后两排还有17张椅子.那么没移走之前就是18张喽,每一排就是有9张喽,条件2也是成立的