How many 9’s are there in the following sequence which are either immediately followed by 9 or immediately preceded by 9?
7 9 3 9 9 2 8 9 6 7 9 3 5 7 9 9 7 5
Four
Two
Five
One
Three
Combinations to be made either is 9 (9) or (9) 9
There are four combinations satisfied the condition.