2014 AMC 8 Problems/Problem 8
Contents
[hide]Problem
Eleven members of the Middle School Math Club each paid the same amount for a guest speaker to talk about problem solving at their math club meeting. They paid their guest speaker . What is the missing digit of this -digit number?
Solution 1
Since all the eleven members paid the same amount, that means that the total must be divisible by . We can do some trial-and-error to get , so our answer is ~SparklyFlowers
Solution 2
We know that a number is divisible by if the odd digits added together minus the even digits added together (or vice versa) is a multiple of . Thus, we have = a multiple of . The only multiple that works here is , as . Thus, ~fn106068
Video Solution (CREATIVE THINKING)
~Education, the Study of Everything
Video Solution
https://youtu.be/mHWTWk-xt0o ~savannahsolver
See Also
2014 AMC 8 (Problems • Answer Key • Resources) | ||
Preceded by Problem 7 |
Followed by Problem 9 | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
All AJHSME/AMC 8 Problems and Solutions |
The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.