Difference between revisions of "1983 AIME Problems/Problem 8"
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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 00:06, 24 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.
