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