GWD11-13

kanba

GWD11-13: 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 of 10 unoccupied seats per row for the front 20 rows.

(2) During the show, there was an average of 20 unoccupied seats per row for the back 15 rows.

答案是E,为什么啊！