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2018 PUMaC Live Round
4.3
4.3
Part of
2018 PUMaC Live Round
Problems
(1)
2018 PUMaC Live Round 4.3
Source:
1/13/2019
Let
0
≤
a
,
b
,
c
,
d
≤
10
0\leq a,b,c,d\leq 10
0
≤
a
,
b
,
c
,
d
≤
10
. For how many ordered quadruples
(
a
,
b
,
c
,
d
)
(a,b,c,d)
(
a
,
b
,
c
,
d
)
is
a
d
−
b
c
ad-bc
a
d
−
b
c
a multiple of
11
?
11?
11
?
PuMAC
Live Round