The pages of a book are numbered from 1 to 128. How many page numbers contain the digit 6?
450
There are 450 of them.
450.
25=20,21,23
874
27: 077,177,277,377,477,577,677,877,977,717,727,737,747,757,767,777,787,797
17
There are 9000 4-digit numbers. 8*9*9*9 = 5832 of them do not contain a 5 The remaining 3168 contain a 5.
1
-2
-5
-5
It would help to know which digit. 0 appears in 9 numbers and each of the others in 18 numbers.
252
There are 6804 such numbers.
The pages of a book are numbered from 1 to 128. How many page numbers contain the digit 6?