Nine of them
It is any one of infinitely many numbers of the form 1407.92nnn where nnn... is any string of digits other than all 0s or all 9s.
79
They can. And if you include repeating 0s and repeating 9s, then all rational numbers can be written with infinitely long repeating digits.
Eleven.
There are 27 of them.
Only 1 exists, and it is "999"
A repeating decimal is a rational number. Its value is(the repeating set of digits)/(as many 9s as there are digits above).
The first 4 digits after the decimal point must be zero and the next digit must be 4 or smaller. If it is 4, then the subsequent digits cannot be a sequence of repeating 9s.
The answer depends on what the ellipses represent. If it is repeating 9s then it is. If it means that the string of digits goes on but with no repeating pattern then it is not.
Oh, dude, you just take the repeating decimal 0.81 and turn it into a fraction. It's like a piece of cake! So, 0.81 repeating is 81/99, and when you simplify that fraction, you get 9/11. Easy peasy, lemon squeezy!
There are 70,674 3's in the first million digits of pi. * * * * * There are 100,230 3s and 100,106 9s. Since the decimal representation of pi is essentially random, the number of times any digit appears should be approximately 10% of the total number of digits. So, for a million digits, there should be around 100,000 of any digit so it should have been immediately apparent that the previous answer was extremely unlikely. In fact it was incorrect to a very large degree!
5
8
Nine of them
It is any one of infinitely many numbers of the form 1407.92nnn where nnn... is any string of digits other than all 0s or all 9s.
79