Question 1 - Transitivity of parallel and perpendicular relations on lines Practice | Prasnya
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Qualifier / Quiz 1
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Mathematics 1
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Week 2
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Parallel and Perpendicular Lines - Parallel and Perpendicular...
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Transitivity of parallel...
Question 1
00:00
Est. 4 min
Marks:
+3.00
0.00
Passage
Let
L
L
be the set of all lines in the
X
Y
XY
plane. Define the relations
R
1
R_1
and
R
2
R_2
as follows:
R
1
=
{
(
ℓ
1
,
ℓ
2
)
∣
ℓ
1
,
ℓ
2
∈
L
and
ℓ
1
is parallel to
ℓ
2
}
R_1 = \{(\ell_1, \ell_2) \mid \ell_1, \ell_2 \in L \text{ and } \ell_1 \text{ is parallel to } \ell_2\}
R
2
=
{
(
ℓ
1
,
ℓ
2
)
∣
ℓ
1
,
ℓ
2
∈
L
and
ℓ
1
is perpendicular to
ℓ
2
}
R_2 = \{(\ell_1, \ell_2) \mid \ell_1, \ell_2 \in L \text{ and } \ell_1 \text{ is perpendicular to } \ell_2\}
Use this information to answer the given subquestions.
Question
Which of the following is/are correct?
Comprehension
Hard Difficulty
13 July 2025
A
If
(
ℓ
1
,
ℓ
2
)
(\ell_1, \ell_2)
and
(
ℓ
2
,
ℓ
3
)
(\ell_2, \ell_3)
are in
R
2
R_2
, then
(
ℓ
1
,
ℓ
3
)
∈
R
1
(\ell_1, \ell_3) \in R_1
.
B
If
(
ℓ
1
,
ℓ
2
)
∈
R
1
(\ell_1, \ell_2) \in R_1
and
(
ℓ
2
,
ℓ
3
)
∈
R
2
(\ell_2, \ell_3) \in R_2
, then
(
ℓ
1
,
ℓ
3
)
∈
R
2
(\ell_1, \ell_3) \in R_2
.
C
If
(
ℓ
1
,
ℓ
2
)
∈
R
2
(\ell_1, \ell_2) \in R_2
and
(
ℓ
2
,
ℓ
3
)
∈
R
1
(\ell_2, \ell_3) \in R_1
, then
(
ℓ
1
,
ℓ
3
)
∈
R
2
(\ell_1, \ell_3) \in R_2
.
D
R
2
R_2
is an equivalence relation.