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2022-23 IOQM India
7
IOQM 2022-23 P-7
IOQM 2022-23 P-7
Source:
October 30, 2022
nt
IOQM
Problem Statement
Find the number of ordered pairs
(
a
,
b
)
(a,b)
(
a
,
b
)
such that
a
,
b
∈
{
10
,
11
,
⋯
,
29
,
30
}
a,b \in \{10,11,\cdots,29,30\}
a
,
b
∈
{
10
,
11
,
⋯
,
29
,
30
}
and \\
\hspace{1cm}
G
C
D
(
a
,
b
)
+
L
C
M
(
a
,
b
)
=
a
+
b
GCD(a,b)+LCM(a,b)=a+b
GC
D
(
a
,
b
)
+
L
CM
(
a
,
b
)
=
a
+
b
.
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