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
If 3 is subtracted from the middle digit of each of the following numbers and then the position of the digits are reversed, which of the following will be the last digit of the middle number after they are arranged in descending order?
Consider a sequence formed by concatenating the positive integers in increasing
order:
12345678910111213 ... Which among the following is the closest to the 2028th digit in
this infinite sequence?