It takes 852 digits to number the pages of a book consecutively. How many pages are there?
How many times is the digit 7 used?
Solution:
There are 320 pages in the book, and the digit 7 was used 62 times.
Pages | Digits |
1 - 9 | 9 digits |
10 - 99 | 180 digits |
100 - 320 | 663 digits |
320 pages | 852 digits |
Pages | Number of 7's |
1 - 100 | 20 sevens |
101 - 200 | 20 sevens |
201 - 300 | 20 sevens |
301 - 320 | 2 sevens |
Correctly solved by:
1. Liz Cotter | Oak Hill, VA |
2. Tom Marino | Winchester, VA |
3. Richard Mocarski | Winchester, VA |
4. Chris Moats | Winchester, VA |
5. Bob Hearn | Winchester, VA |