2010 AMC 10A Problems/Problem 9
Problem
A palindrome, such as , is a number that remains the same when its digits are reversed. The numbers
and
are three-digit and four-digit palindromes, respectively. What is the sum of the digits of
?
Solution
is at most
, so
is at most
. The minimum value of
is
. However, the only palindrome between
and
is
, which means that
must be
.
It follows that is
, so the sum of the digits is
.
See also
2010 AMC 10A (Problems • Answer Key • Resources) | ||
Preceded by Problem 8 |
Followed by Problem 10 | |
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All AMC 10 Problems and Solutions |