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2011 AIME Problems
6
Interesting ordered quadruples
Interesting ordered quadruples
Source: 2011 AIME II #6
March 31, 2011
probability
AMC
AIME
Problem Statement
Define an ordered quadruple of integers
(
a
,
b
,
c
,
d
)
(a, b, c, d)
(
a
,
b
,
c
,
d
)
as interesting if
1
≤
a
<
b
<
c
<
d
≤
10
1 \le a<b<c<d \le 10
1
≤
a
<
b
<
c
<
d
≤
10
, and
a
+
d
>
b
+
c
a+d>b+c
a
+
d
>
b
+
c
. How many ordered quadruples are there?
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