UG Mathematics Booster Test 2 - Types of Relations
๐ Answers are locked once submitted โ results and explanations appear at the end.
QUESTION 1 OF 20
Let S be the set of all squares. A relation R on S is defined by
(Sโ,Sโ) โ R if Area(Sโ) โ Area(Sโ) = โ50.
Given that every square in S has area 10 square units, determine the nature of R.
QUESTION 2 OF 20
Let E be the set of all impossible events in a sample space. A relation R on E is defined by
(Eโ,Eโ) โ R if P(Eโ)+P(Eโ)=0.
What best describes the relation R?
QUESTION 3 OF 20
Let R be a relation on the set of continuous functions defined by
(f,g) โ R if
โซโแต(f(x)โg(x)) dx = 0.
For the relation R to be reflexive, the value of the integral must be:
QUESTION 4 OF 20
Let R be a relation defined on the set of all lines in the Cartesian plane such that
(Lโ,Lโ) โ R if Lโ โ Lโ.
Why is this relation symmetric but not reflexive?
QUESTION 5 OF 20
Consider a relation R on stock data arrays. (A, B) โ R if array A's 5-day moving average is greater than array B's. If (A, B) โ R and (B, C) โ R, what is the required condition for R to be transitive?
QUESTION 6 OF 20
For relation R = {(a, b): a is a subset of b} applied to set operations, which of the following logically implies transitivity?
I. If Set A โ Set B
II. And Set B โ Set C
III. Then Set A โ Set C
IV. Set A โฉ Set B = ฯ
QUESTION 7 OF 20
Match the specific relation on Set A = {1, 2, 3} to its reflexive status:
| List I | List II |
|---|---|
| 1. {(1,1), (2,2), (3,3)} | a. Not reflexive, missing (1,1), (2,2), (3,3) |
| 2. {(1,1), (2,2), (3,3), (1,2)} | b. Reflexive, exact identity relation |
| 3. {(1,1), (2,2)} | c. Reflexive, contains extra elements |
| 4. {(1,2), (2,3)} | d. Not reflexive, missing (3,3) |
QUESTION 8 OF 20
Arrange the steps to check if relation R = {(x,y) : x - y is an integer} is reflexive for all real numbers x:
1. Thus, R is reflexive.
2. Substitute y with x to check (x, x).
3. 0 is an integer.
4. Calculate x - x = 0.
QUESTION 9 OF 20
Assertion (A): The relation R = {(1, 2), (2, 1)} on set {1, 2, 3} is symmetric.
Reason (R): For every (a, b) in R, the pair (b, a) is also present in R.
QUESTION 10 OF 20
Relation R on a set of vectors defines (A, B) โ R if the cross product A ร B = 0. If (A, B) โ R, does it imply (B, A) โ R?
QUESTION 11 OF 20
An EMI relation R on loan accounts asserts (L1, L2) โ R if EMI of L1 is exactly Rs. 500 less than EMI of L2. Is this relation transitive?
QUESTION 12 OF 20
Regarding the relation R = {(L1, L2) : L1 is perpendicular to L2} on a set of lines, identify the INCORRECT statement:
QUESTION 13 OF 20
QUESTION 14 OF 20
QUESTION 15 OF 20
For R = {(a, b) : 2 divides a - b} defined on integers, which elements form the equivalence class [0]?
QUESTION 16 OF 20
For the equivalence relation R = {(a, b): 3 divides a - b} on set Z, the equivalence classes can be represented correctly by which combinations?
I. = {..., -6, -3, 0, 3, 6, ...}
II. = {..., -5, -2, 1, 4, 7, ...}
III. = {..., -4, -1, 2, 5, 8, ...}
IV. = {1, 2, 3, 4}
QUESTION 17 OF 20
If subsets E and O form a partition of the set of Integers (Z) under a specific equivalence relation, what is the intersection of E and O?
QUESTION 18 OF 20
Assertion (A): For equivalence classes Aโ,Aโ,Aโ forming a partition of set Z,
Aโ โช Aโ โช Aโ = Z
Reason (R): Partitions of a set generated by an equivalence relation must completely cover the original set.
QUESTION 19 OF 20
Match the geometry relation to its properties:
| List I | List II |
|---|---|
| 1. T1 is congruent to T2 | a. Reflexive, Symmetric, Transitive (Equivalence on lines) |
| 2. T1 is similar to T2 | b. Symmetric only |
| 3. L1 is parallel to L2 | c. Equivalence on triangles (size and shape identical) |
| 4. L1 is perpendicular to L2 | d. Equivalence on triangles (shape identical, size varies) |
QUESTION 20 OF 20
Arrange the steps proving the symmetric property FAILS for the relation "a divides b" on Natural numbers:
1. Therefore, 4 does not divide 2, so (4, 2) โ R.
2. Let a = 2 and b = 4.
3. This proves the relation is not symmetric.
4. 2 divides 4, so (2, 4) โ R.
Test Complete!
Answer Review
1 Let S be the set of all squares. A relation R on S is defined by
(Sโ,Sโ) โ R if Area(Sโ) โ Area(Sโ) = โ50.
Given that every square in S has area 10 square units, determine the nature of R.
Every square has equal area Difference of areas becomes 0 Condition โ50 is impossible
Since every square has area 10 square units, for any pair Sโ and Sโ: Area(Sโ) โ Area(Sโ) = 10 โ 10 = 0. The required condition โ50 can never occur. Hence no ordered pair satisfies the relation, making R an empty relation. Therefore Option B is correct.
- Option A โ Universal relation requires all possible ordered pairs to satisfy the condition.
- Option C โ Reflexivity requires every element related to itself, which fails here.
- Option D โ Empty relation trivially satisfies transitivity, but its primary classification here is empty relation.
Used: Substitution
Application:
- Substitute given area values directly into the relation condition.
Final Logic:
- 10 โ 10 โ โ50, so no ordered pair exists.
"Impossible condition โ Empty relation"
2 Let E be the set of all impossible events in a sample space. A relation R on E is defined by
(Eโ,Eโ) โ R if P(Eโ)+P(Eโ)=0.
What best describes the relation R?
Impossible events have probability 0 Sum of two impossible events remains 0 Every pair satisfies relation
For impossible events, P(Eโ)=0 and P(Eโ)=0. Therefore: \(0+0=0\) Every ordered pair satisfies the relation condition. Hence all pairs belong to R, making it the universal relation on E. Therefore Option B is correct.
- Option A โ Relation is not empty because every pair satisfies the condition.
- Option C โ Relation is symmetric since addition is commutative.
- Option D โ Universal relation has more properties than only transitivity.
Used: Substitution
Application:
- Use probability value of impossible events directly in relation equation.
Final Logic:
- All ordered pairs satisfy the condition, giving universal relation.
"Impossible event โ Probability zero"
3 Let R be a relation on the set of continuous functions defined by
(f,g) โ R if
โซโแต(f(x)โg(x)) dx = 0.
For the relation R to be reflexive, the value of the integral must be:
Reflexive means f relates to itself f(x) โ f(x) becomes 0 Integral of zero equals zero
For reflexivity, every function f must satisfy (f,f) โ R. Then: \(\int_{a}^{b}\,(f(x)-f(x))โdx=\int_{a}^{b}\,0โdx=0\) Hence the integral must equal 0. Therefore Option C is correct.
- Option A โ Reflexive condition does not require integral value 1.
- Option B โ f(x) is a function, not a constant integral value.
- Option D โ Integral of zero cannot become infinite.
Used: Substitution
Application:
- Replace g(x) with f(x) to test reflexivity directly.
Final Logic:
- f(x)โf(x)=0, so integral equals 0.
"Self minus self = zero"
4 Let R be a relation defined on the set of all lines in the Cartesian plane such that
(Lโ,Lโ) โ R if Lโ โ Lโ.
Why is this relation symmetric but not reflexive?
Perpendicularity works both ways No line is perpendicular to itself Hence symmetric but not reflexive
If Lโ is perpendicular to Lโ, then Lโ is also perpendicular to Lโ, satisfying symmetry. However, a line cannot be perpendicular to itself, so reflexivity fails. Therefore Option D correctly explains both properties simultaneously.
- Option A โ A line is never perpendicular to itself.
- Option B โ Perpendicular lines intersect exactly at 90ยฐ.
- Option C โ Parallelism and perpendicularity are different concepts.
Used: Contextual/Tonal Matching
Application:
- Interpret geometric meaning of perpendicular lines carefully.
Final Logic:
- Perpendicularity reverses symmetrically but fails self-relation.
"Perpendicular both ways, never self"
5 Consider a relation R on stock data arrays. (A, B) โ R if array A's 5-day moving average is greater than array B's. If (A, B) โ R and (B, C) โ R, what is the required condition for R to be transitive?
Greater-than relation is transitive A > B and B > C imply A > C Hence transitivity holds
If A's moving average is greater than B's, and B's is greater than C's, then by transitivity of inequalities: A > C. Thus the relation remains transitive only when A's average exceeds C's average. Therefore Option D is correct.
- Option A โ Opposite inequality contradicts transitivity.
- Option B โ Equality cannot follow from strict greater-than conditions.
- Option C โ Value of B's average is irrelevant.
Used: Contextual/Tonal Matching
Application:
- Apply transitivity property of inequalities directly.
Final Logic:
- Greater-than relation naturally chains forward.
"Greater-than keeps flowing"
6 For relation R = {(a, b): a is a subset of b} applied to set operations, which of the following logically implies transitivity?
I. If Set A โ Set B
II. And Set B โ Set C
III. Then Set A โ Set C
IV. Set A โฉ Set B = ฯ
Subset relation is transitive Chain of subsets implies larger inclusion Intersection condition unnecessary
If A โ B and B โ C, then logically A โ C. This is the exact transitive property of subset relation. Statement IV about intersection being empty is unrelated to transitivity. Hence Statements I, II, and III together correctly define transitivity, making Option A correct.
- Option B โ Intersection condition is unrelated to transitivity.
- Option C โ Missing initial subset condition.
- Option D โ Statement III alone cannot establish implication chain.
Used: Option Grouping
Application:
- Identify statements forming logical implication chain.
Final Logic:
- Subset relation transfers through intermediate sets.
"Subset chain passes forward"
7 Match the specific relation on Set A = {1, 2, 3} to its reflexive status:
| List I | List II |
|---|---|
| 1. {(1,1), (2,2), (3,3)} | a. Not reflexive, missing (1,1), (2,2), (3,3) |
| 2. {(1,1), (2,2), (3,3), (1,2)} | b. Reflexive, exact identity relation |
| 3. {(1,1), (2,2)} | c. Reflexive, contains extra elements |
| 4. {(1,2), (2,3)} | d. Not reflexive, missing (3,3) |
Reflexive relation contains all self-pairs Missing any self-pair breaks reflexivity Extra pairs do not matter
Relation 1 is exact identity relation โ b. Relation 2 contains all self-pairs plus extra element โ c. Relation 3 misses (3,3) โ d. Relation 4 misses all self-pairs โ a. Thus the correct matching is Option B.
- Option A โ Relation 2 is still reflexive despite extra pair.
- Option C โ Relation 1 is reflexive, not non-reflexive.
- Option D โ Relation 4 lacks all required self-pairs.
Used: Option Grouping
Application:
- Check presence or absence of all self-pairs systematically.
Final Logic:
- Reflexive requires every (a,a) pair.
"All self-pairs must appear"
8 Arrange the steps to check if relation R = {(x,y) : x - y is an integer} is reflexive for all real numbers x:
1. Thus, R is reflexive.
2. Substitute y with x to check (x, x).
3. 0 is an integer.
4. Calculate x - x = 0.
Start by checking self-pair Difference becomes zero Since zero is integer, reflexive holds
To test reflexivity, first substitute y=x. Then calculate xโx=0. Since 0 is an integer, the relation condition holds for every x. Therefore the relation is reflexive. Hence correct order is 2 โ 4 โ 3 โ 1, making Option C correct.
- Option A โ Integer conclusion appears before calculation.
- Option B โ Begins with conclusion instead of substitution.
- Option D โ Final conclusion cannot appear first.
Used: Contextual/Tonal Matching
Application:
- Arrange proof statements in logical mathematical order.
Final Logic:
- Substitute โ calculate โ verify โ conclude.
"Self-check gives zero integer"
9 Assertion (A): The relation R = {(1, 2), (2, 1)} on set {1, 2, 3} is symmetric.
Reason (R): For every (a, b) in R, the pair (b, a) is also present in R.
Symmetry requires reverse pair presence Reverse ordered pairs exist here Reason correctly explains assertion
The relation contains both (1,2) and (2,1). Hence whenever (a,b) belongs to R, the reverse pair (b,a) also belongs to R. This exactly satisfies the definition of symmetry. Therefore both Assertion and Reason are true, and Reason correctly explains Assertion.
- Option A โ Both statements match symmetric relation definition.
- Option B โ Reason is mathematically correct.
- Option D โ Assertion correctly identifies symmetric relation.
Used: Elimination
Application:
- Check whether every ordered pair has its reverse pair.
Final Logic:
- Presence of reverse pairs guarantees symmetry.
"Symmetric means pair reversal"
10 Relation R on a set of vectors defines (A, B) โ R if the cross product A ร B = 0. If (A, B) โ R, does it imply (B, A) โ R?
Cross product reverses sign Zero vector remains unchanged under sign change Hence relation is symmetric
For vectors: A ร B = โ(B ร A). If A ร B = 0, then: B ร A = โ0 = 0. Therefore the reverse ordered pair also satisfies the condition, making the relation symmetric. Hence Option D is correct.
- Option A โ Cross product reversal does not always equal 1.
- Option B โ Parallel vectors can have zero cross product.
- Option C โ Cross product is anti-commutative, not commutative.
Used: Contextual/Tonal Matching
Application:
- Use anti-commutative property of vector cross product.
Final Logic:
- Negative of zero is still zero.
"โ0 is still 0"
11 An EMI relation R on loan accounts asserts (L1, L2) โ R if EMI of L1 is exactly Rs. 500 less than EMI of L2. Is this relation transitive?
Transitivity needs same relation preserved Differences accumulate numerically Final difference becomes Rs.1000
Suppose EMI(L1)=EMI(L2)โ500 and EMI(L2)=EMI(L3)โ500. Then: \(EMI(L1)=EMI(L3)-1000\) Thus L1 is not Rs.500 less than L3. Therefore the relation fails transitivity. Hence Option A is correct.
- Option B โ Difference changes to Rs.1000, not Rs.500.
- Option C โ Fixed loan amounts do not affect logical transitivity.
- Option D โ EMIs are numerical quantities and are comparable.
Used: Substitution
Application:
- Apply the relation step-by-step using actual numerical differences.
Final Logic:
- 500 + 500 = 1000, so transitivity fails.
"Differences add up"
12 Regarding the relation R = {(L1, L2) : L1 is perpendicular to L2} on a set of lines, identify the INCORRECT statement:
Perpendicularity is not transitive Two lines perpendicular to same line become parallel Hence statement A is incorrect
If L1 โฅ L2 and L2 โฅ L3, then L1 and L3 are parallel, not perpendicular. Therefore perpendicularity is not transitive. Hence Option A is incorrect. Options B, C, and D correctly describe perpendicular relation properties.
- Option B โ Correct because perpendicular lines to same line become parallel.
- Option C โ Perpendicularity works both ways, so symmetry holds.
- Option D โ No line is perpendicular to itself, so reflexivity fails.
Used: Elimination
Application:
- Test geometric properties of perpendicular lines carefully.
Final Logic:
- Perpendicular-to-same-line implies parallelism, not perpendicularity.
"โฅ then โฅ gives โฅ"
13
Equivalence relations partition sets Partitions create disjoint subsets Their union covers the entire set
The passage states that equivalence relations partition a set into mutually disjoint subsets whose union equals the original set. This property belongs specifically to equivalence relations, which combine reflexive, symmetric, and transitive properties. Therefore Option B is correct.
- Option A โ Transitivity alone cannot create complete partitions.
- Option C โ Reflexivity alone is insufficient for equivalence classes.
- Option D โ Empty relation does not partition meaningfully.
Used: Contextual/Tonal Matching
Application:
- Use the exact statement given in the passage.
Final Logic:
- Partitions arise directly from equivalence relations.
"Equivalence โ Partition"
14
Different equivalence classes are disjoint Related elements stay in same class Hence x and y are unrelated
In equivalence relations, elements from different equivalence classes are not related to each other. Since x belongs to Aโ and y belongs to distinct class Aโ, they cannot satisfy the relation R. Therefore Option D is correct.
- Option A โ Symmetry applies only when relation already exists.
- Option B โ Different class membership does not imply equality.
- Option C โ Reflexivity concerns self-relations only.
Used: Elimination
Application:
- Use the disjoint property of equivalence classes.
Final Logic:
- Different equivalence classes contain unrelated elements.
"Different classes, no relation"
15 For R = {(a, b) : 2 divides a - b} defined on integers, which elements form the equivalence class [0]?
[0] contains numbers related to 0 Difference with 0 must be divisible by 2 Hence all even integers belong
For any integer a to belong to [0], we need: \(2โฃ(a-0)\) This means a must be divisible by 2. Therefore [0] consists of all even integers. Hence Option C is correct.
- Option A โ Positive odd numbers are not divisible by 2.
- Option B โ Odd integers differ from 0 by odd numbers.
- Option D โ Prime numbers are not necessarily even.
Used: Substitution
Application:
- Replace b by 0 in divisibility condition directly.
Final Logic:
- Numbers related to 0 must be even.
"Class [0] = even numbers"
16 For the equivalence relation R = {(a, b): 3 divides a - b} on set Z, the equivalence classes can be represented correctly by which combinations?
I. = {..., -6, -3, 0, 3, 6, ...}
II. = {..., -5, -2, 1, 4, 7, ...}
III. = {..., -4, -1, 2, 5, 8, ...}
IV. = {1, 2, 3, 4}
Modulo 3 gives three equivalence classes Numbers differ by multiples of 3 Finite set IV is incorrect
Integers modulo 3 form exactly three equivalence classes: [0], [1], and [2]. Sets I, II, and III correctly represent these classes since consecutive elements differ by 3. Set IV is not closed under modulo-3 equivalence. Therefore Option A is correct.
- Option B โ Set IV is incomplete and not an equivalence class.
- Option C โ Omits one valid modulo-3 class.
- Option D โ Includes invalid finite representation.
Used: Option Grouping
Application:
- Identify sets formed by numbers differing by multiples of 3.
Final Logic:
- Modulo 3 partitions integers into three infinite classes.
"Modulo 3 gives three groups"
17 If subsets E and O form a partition of the set of Integers (Z) under a specific equivalence relation, what is the intersection of E and O?
Partition subsets are disjoint Even and odd integers never overlap Their intersection is empty
A partition divides a set into mutually disjoint subsets. Since E and O represent separate equivalence classes (even and odd integers), no integer can belong to both simultaneously. Therefore: \(E\cap O=\emptyset\) Hence Option B is correct.
- Option A โ Entire set cannot equal the intersection.
- Option C โ 0 is only even, not odd.
- Option D โ 1 is only odd, not even.
Used: Odd One Out
Application:
- Use the mutually disjoint property of partitions.
Final Logic:
- Distinct equivalence classes never overlap.
"Partition means no overlap"
18 Assertion (A): For equivalence classes Aโ,Aโ,Aโ forming a partition of set Z,
Aโ โช Aโ โช Aโ = Z
Reason (R): Partitions of a set generated by an equivalence relation must completely cover the original set.
Partitions cover the whole set Equivalence classes form partitions Reason directly explains assertion
Equivalence classes generated by an equivalence relation partition the original set completely. Therefore the union of all equivalence classes equals the full set Z. Both Assertion and Reason are true, and the Reason correctly explains the Assertion. Hence Option C is correct.
- Option A โ Both statements are mathematically correct.
- Option B โ Reason is true and foundational.
- Option D โ Assertion follows directly from partition property.
Used: Contextual/Tonal Matching
Application:
- Connect partition definition with union property directly.
Final Logic:
- Partitions always cover the entire original set.
"All classes together give whole set"
19 Match the geometry relation to its properties:
| List I | List II |
|---|---|
| 1. T1 is congruent to T2 | a. Reflexive, Symmetric, Transitive (Equivalence on lines) |
| 2. T1 is similar to T2 | b. Symmetric only |
| 3. L1 is parallel to L2 | c. Equivalence on triangles (size and shape identical) |
| 4. L1 is perpendicular to L2 | d. Equivalence on triangles (shape identical, size varies) |
Congruence preserves size and shape Similarity preserves shape only Perpendicularity is symmetric only
Congruence is an equivalence relation on triangles โ c. Similarity preserves shape but not size โ d. Parallelism on lines is reflexive, symmetric, and transitive โ a. Perpendicularity is symmetric but neither reflexive nor transitive โ b. Thus Option D is correct.
- Option A โ Congruence is not merely symmetric.
- Option B โ Parallelism is not represented correctly.
- Option C โ Perpendicularity is not equivalence relation.
Used: Option Grouping
Application:
- Match geometric relations with standard relation properties.
Final Logic:
- Only parallelism and congruence form equivalence relations.
"Congruent = same size and shape"
20 Arrange the steps proving the symmetric property FAILS for the relation "a divides b" on Natural numbers:
1. Therefore, 4 does not divide 2, so (4, 2) โ R.
2. Let a = 2 and b = 4.
3. This proves the relation is not symmetric.
4. 2 divides 4, so (2, 4) โ R.
Begin with example values Check forward divisibility relation Reverse relation fails, disproving symmetry
Choose a=2 and b=4. Since 2 divides 4, (2,4) โ R. But 4 does not divide 2, so (4,2) โ R. Therefore the reverse pair fails, proving the relation is not symmetric. Thus the correct sequence is 2 โ 4 โ 1 โ 3.
- Option B โ Begins with conclusion before choosing example.
- Option C โ Logical order is completely reversed.
- Option D โ Reverse divisibility checked before original relation.
Used: Contextual/Tonal Matching
Application:
- Arrange statements according to mathematical proof sequence.
Final Logic:
- Example โ verify โ reverse fails โ conclude.
"2 divides 4, not reverse"
