If 8000 books need to be placed in boxes and each box can contain at most 9 books. How many books will be in the last unfilled box?
Choose the correct choice from the following answers:
A) 8 books
B) 9 books
C) 1 book
D) 5 books
E) 4 books
The number of books that can be placed in boxes of 9 books is the first number that is divisible by 9 that occurs before 8000.   In order to divide the sum in 9 parts, the amount must be divisible by 9   Divisibility rule of 9: The sum of the digits must be divisible by 9   Sum of digits of 8000 = 8 and 0 is divisible by 9.   Hence, we need to remove 8 to this number for it to be divisible by 9   Correct Option:8 books
<result>A</result>
If 8000 books need to be placed in boxes and each box can contain at most 9 books. How many books will be in the last unfilled box?