Mock AIME 2 Pre 2005 Problems/Problem 5
Problem
Let be the set of integers
for which
, an infinite decimal that has the property that
for all positive integers
. Given that
is prime, how many positive integers are in
? (The
are digits.)
Solution
Let , the first
decimal digits of
. We can see that
so
is the set that contains all divisors of
except for
. Since
the number
has
divisors and our answer is
-MP8148
See also
Mock AIME 2 Pre 2005 (Problems, Source) | ||
Preceded by Problem 4 |
Followed by Problem 6 | |
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