To number the pages in a math book, the printer used 2,989 digits.
How many pages are in the book?
Solution to the Problem:
The answer is 1,024 pages.A book of 99 pages needs 9 + 2 x 90 = 189 digits.
A book of 999 pages needs 9 + 2 x 90 + 3 x 900= 2,889 digits.
A book of n pages needs 2,889 + 4 x (n - 999) digits.
Set 2889 + 4 (n - 999) = 2,989.
Then n = 1024 pages
Correctly solved by:
| 1. Ivy Joseph | Pune, Maharashtra, India |
| 2. Colin (Yowie) Bowey | Beechworth, Victoria, Australia |
| 3. Joshua Mangin | --------- |
| 4. Katherine Grossman |
Redlands Middle School, Grand Junction, Colorado |
| 5. Kamri Hutchings |
Mountain View High School, Mountain View, Wyoming |
| 6. Adan Vargas |
Mountain View High School, Mountain View, Wyoming |