Can you find the missing number in the series below

1 5 9 2 6 10 3 ? 11 4 8 12

7

Series given in the problem :
1 5 9 2 6 10 3 ? 11 4 8 12
Let us break the series as :
1 5 9
2 6 10
3 ? 11
4 8 12

Now, read the numbers from left, top to bottom. The missing number is obviously 7.

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