There are 2892 digits.
1100
There are 116 1s in the first 1000 digits of pi.
2625
1000
There are 120 of them.
How many strings of three digits are there? 000 to 999, or a total of 1000. How many strings of three digits contain the same three digits? That's 000, 111, 222 ... 999! ten in total. The difference is your answer: 1000-10 = 990.
123
2890
1000
Not couting 1 and 1000, there would be 998 numbers.
there is 116 ones in the 1000 digits of pi. heres a site with the answer http://www.eveandersson.com/pi/precalculated-frequencies