How many 1's are there preceded by 2 but not followed by 0?
5 9 3 2 1 7 4 2 6 9 7 4 2 1 3 2 8 7 0 1 3 8 3 2 5 6 7 4 3 9 5 8 2 2 1 0 7 4 6 3
Pick:  A) 4  B) 2  C) 6  D) 8  E) 9
2 1 7   2 1 3   Only at these places 2 is preceded by 2 but not followed by 0   Answer: 2
<result>B</result>
How many 1's are there preceded by 2 but not followed by 0?
5 9 3 2 1 7 4 2 6 9 7 4 2 1 3 2 8 7 0 1 3 8 3 2 5 6 7 4 3 9 5 8 2 2 1 0 7 4 6 3