11
10
9
8
Answer is Wrong!
Answer is Right!
The missing number is 10.
The numbers in the sequence are all multiples of 3, except for the last number, which is 1 less than the next multiple of 3. Therefore, the missing number must be 1 less than the last number, which is 10.
A. 11 is not a multiple of 3.
B. 10 is a multiple of 3 and is 1 less than the next multiple of 3, which is 11.
C. 9 is not a multiple of 3.
D. 8 is not a multiple of 3 and is not 1 less than the next multiple of 3.