Q60.Let 50∪ = ∪n = T , where each Xi contains 10 elements and each Yi contains 5 elements. If each element i=1Xi i=1Yi of the set T is an element of exactly 20 of sets Xi 's and exactly 6 of sets Yi 's then n is equal to : (1) 15 (2) 50 (3) 45 (4) 30
What This Question Tests
This question involves applying a generalized principle of inclusion-exclusion or counting by two ways. It requires carefully counting the total number of elements based on how many sets each element belongs to for both families of sets (Xᵢ and Yᵢ) to determine the value of 'n'.
Concepts Tested
Formulas Used
|∪Aᵢ| = (1/k) ∑|Aᵢ| if each element is in k sets
📚 NCERT Sections This Tests
5.18 — What Is Crystal Field Splitting Energy? How Does The Magnitude Of Do Decide
Chemistry Class 11 · Chapter 5
5.18 What is crystal field splitting energy? How does the magnitude of Do decide the actual configuration of d orbitals in a coordination entity?
5.28 — How Many Ions Are Produced From The Complex Co(Nh3)6Cl2 In Solution?
Chemistry Class 11 · Chapter 5
5.28 How many ions are produced from the complex Co(NH3)6Cl2 in solution? (i) 6 (ii) 4 (iii) 3 (iv) 2 139 Coordination Compounds Reprint 2025-26
5.15 — Discuss The Nature Of Bonding In The Following Coordination Entities On The
Chemistry Class 11 · Chapter 5
5.15 Discuss the nature of bonding in the following coordination entities on the basis of valence bond theory: (i) [Fe(CN)6] 4– (ii) [FeF6] 3– (iii) [Co(C2O4)3]3– (iv) [CoF6] 3–
📋 Question Details
- Chapter
- Sets Relations Functions
- Topic
- Properties of sets (Union, Cardinality)
- Year
- 2020
- Shift
- 04 Sep Shift 2
- Q Number
- Q60
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 1: Sets
More from this Chapter
Q86.Let R be the real line. Consider the following subsets of the plane R × R. S = {(x, y) : y = x + 1 and 0 < x < 2}, T = {(x, y) : x −y is an integer }. Which one of the following is true? (1) neither S nor T is an equivalence relation on R (2) both S and T are equivalence relations on R (3) S is an equivalence relation on R but T is not (4) T is an equivalence relation on R but S is not
Q91.Let f : N →Y be a function defined as f(x) = 4x + 3, where Y = {y ∈N : y = 4x + 3 for some x ∈N}. Show that f is invertible and its inverse is (1) g(y) = 3y+43 (2) g(y) = 4 + y+34 (3) g(y) = y+34 (4) g(y) = y−34 1 ), if x ≠1 x−1 . Then which one of the following is true?
Q73.If A, B and C are three sets such that A ∩B = A ∩C and A ∪B = A ∪C , then (1) A = B (2) A = C (3) B = C (4) A ∩B = ϕ
Q77.For real x, let f(x) = x3 + 5x + 1, then (1) f is one-one but not onto R (2) f is onto R but not one-one (3) f is one-one and onto R (4) f is neither one-one nor onto R