Question

Count each 1 in the following sequence of numbers
that is immediately followed by 2, if 2 is not
immediately followed by 3. How many such 1's are
there?
121 345 12352126145112412321752
125
ans.
2
5
4.
3​

Answer 1

Answer:

4 is the answer

Explanation:

See in 121, 1 follows 2 and 2 not follows 3, so this 1 can be considered. Similarly, this occurs in 126, 124 and 125.