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National and Regional Contests
India Contests
ISI B.Stat Entrance Exam
2007 ISI B.Stat Entrance Exam
6
6
Part of
2007 ISI B.Stat Entrance Exam
Problems
(1)
Set: {f(r,r):r in S}=S
Source: ISI (BS) 2007 #6
4/11/2012
Let
S
=
{
1
,
2
,
⋯
,
n
}
S=\{1,2,\cdots ,n\}
S
=
{
1
,
2
,
⋯
,
n
}
where
n
n
n
is an odd integer. Let
f
f
f
be a function defined on
{
(
i
,
j
)
:
i
∈
S
,
j
∈
S
}
\{(i,j): i\in S, j \in S\}
{(
i
,
j
)
:
i
∈
S
,
j
∈
S
}
taking values in
S
S
S
such that (i)
f
(
s
,
r
)
=
f
(
r
,
s
)
f(s,r)=f(r,s)
f
(
s
,
r
)
=
f
(
r
,
s
)
for all
r
,
s
∈
S
r,s \in S
r
,
s
∈
S
(ii)
{
f
(
r
,
s
)
:
s
∈
S
}
=
S
\{f(r,s): s\in S\}=S
{
f
(
r
,
s
)
:
s
∈
S
}
=
S
for all
r
∈
S
r\in S
r
∈
S
Show that
{
f
(
r
,
r
)
:
r
∈
S
}
=
S
\{f(r,r): r\in S\}=S
{
f
(
r
,
r
)
:
r
∈
S
}
=
S
function
algebra unsolved
algebra