How many 5s are there in the number series each of which is immediately followed by 4 but not immediately preceded by 6?
Series: 456 656 455 455 654 456 456 5454
🎥 Video solution / Text Solution of this question is given below:
We check every 5 followed by 4 and not preceded by 6.
Only the two 5s inside 5454 satisfy this condition.