1983 AIME Problems/Problem 8: Difference between revisions
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== Problem == | == Problem == | ||
What is the largest 2-digit prime factor of the integer <math> | What is the largest 2-digit prime factor of the integer <math>{200\choose 100}</math>? | ||
== Solution == | == Solution == | ||
Revision as of 23:06, 23 July 2006
Problem
What is the largest 2-digit prime factor of the integer
?
Solution
Expanding the binomial coefficient, we get
.
Therefore, our two digit prime
must satisfy
. The largest such prime is
, which is our answer.