（A） 2
（B）
（C） -
（D） -1
（E） -2
28. If 720 is the product of the consecutive integers beginning with 2 and ending with n， what is the value of n-1？
（A） 5
（B） 6
（C） 8
（D） 11
（E） 23
29. When it was found that 150 more tickets for the school play were sold than the seating capacity of the auditorium. It was decided to have two performances. if the total number of tickets sold was equal to the total number who attended and if the auditorium was full for each of the two performances， what is the seating capacity of the auditorium？
（A） 100
（B） 200
（C） 225
（D） 300
（E） 450
30. If n = pqr， where p， q， and r are three different positive prime numbers， how many different positive divisors does n have， including l and n？
（A） 3
（B） 5
（C） 6
（D） 7
（E） 8
