2006 AMC 8 Problems/Problem 11
Problem
How many two-digit numbers have digits whose sum is a perfect square?
Solution
There is integer whose digits sum to : .
There are integers whose digits sum to : .
There are integers whose digits sum to : .
There are integers whose digits sum to : .
Two digits cannot sum to or any greater square since the greatest sum of digits of a two-digit number is .
Thus, the answer is .
See Also
2006 AMC 8 (Problems • Answer Key • Resources) | ||
Preceded by Problem 10 |
Followed by Problem 12 | |
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