In the following number series, how many times do 1, 3 and 7 appear together, with 7 in the middle and 1 and 3 on either side of 7?
2, 9, 7, 3, 1, 7, 3, 7, 7, 1, 3, 3,
1, 7, 3, 8, 5, 7, 1, 3, 7, 7, 1, 7,
3, 9, 0, 6
A
3
B
4
C
5
D
More than 5
Correct Option:
A
Explanation
We need occurrences where 7 is in the middle and 1 and 3 are on its two sides, i.e., 1-7-3 or 3-7-1. Scanning the sequence gives three valid 1-7-3 groups, so the count is 3.
