9
10
7
8
Answer is Wrong!
Answer is Right!
The missing term is 7.
The sequence is a simple alternating addition and subtraction of 1 and 2.
1 + 1 = 2
2 – 2 = 0
0 + 3 = 3
3 – 2 = 1
1 + 5 = 6
6 – 2 = 4
4 + 7 = 11
11 – 2 = 9
9 + 10 = 20
Therefore, the missing term is 7.