Theater M has 25 rows with 27 seats in each row. How many of the seats were occupied during a certain show?
(1) During the show, there was an average (arithmetic mean) of 10 unoccupied seats per row for the front 20 rows.
(2) During the show, there was an average (arithmetic mean) of 20 unoccupied seats per row for the back 15 rows.
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
答案為Ｅ
想請教各問大大，答案為何不是D阿，(1) and (2)分別可以解出已經使用中的位子了阿??
就(1)而言：前20排是平均10個空的所以total occupied=20*(27-10)+5*27
就(2)而言：total occupied=10*27+15*7
可否請各位大大幫我解答....
