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2010 Stanford Mathematics Tournament
24
24
Part of
2010 Stanford Mathematics Tournament
Problems
(1)
SMT 2010 General #24
Source:
2/11/2012
We are given a coin of diameter
1
2
\frac{1}{2}
2
1
and a checkerboard of 1\times1 squares of area
2010
×
2010
2010\times2010
2010
×
2010
. We toss the coin such that it lands completely on the checkerboard. If the probability that the coin doesn't touch any of the lattice lines is
a
2
b
2
\frac{a^2}{b^2}
b
2
a
2
where
a
b
\frac{a}{b}
b
a
is a reduced fraction, find
a
+
b
a+b
a
+
b
geometry
probability