For example, how many whole numbers contain an eight? Well, for whole numbers less than ten, it's just eight itself, so that's 10% and for whole numbers less than 100, there are 8, 18, 28, 38, 48, 58, 68, 78, the 80s, and 98, so that's 19 out of 100, which is 19%; the percentage went up, and for whole numbers less than 1,000, we have those whole numbers again, but with a 1 through a 9 in front, counting all of the 800s. So, that's 19*9=171+100=271. 271/1,000=27.1%, so it's going up. We can do the similar thing for whole numbers less than 10,000: 9*271=2,439+1,000=3,439. 3,439/10,000=34.39%. It's going up every time. Because of this happening, is it possible that all whole numbers contain any of the digits zero through nine (just one out of the ten)?
2026-03-27 13:27:36.1774618056
On
Does almost every whole number integer contain any of the digits zero through nine?
898 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
2
There are 2 best solutions below
0
On
Yes, as you look at larger and larger $N$, the fraction of numbers in the range $1,\ldots,N$ containing all digits in their decimal expansion approaches $1$. For example, if $N = 10^M$ then we are choosing $M$ digits at random. The probability that you don't contain all digits is at most $10(9/10)^M$, and this tends to zero as $M$ tends to infinity.
The number of integers smaller than $10^n$ and containing at least one $8$ is equal to $$10^n - 9^n$$
This is because the number of integers without eights is $9^8$.
This means that the numbers with at least one eight represent $$1 - \left(\frac9{10}\right)^n$$ of all numbers, a number limiting to $1$ as $n$ becomes large.