If A = {1, 2, 3, 4, 5} , B = {1, 4, 5} and R = {(a, b): a ∈ A, b ∈ B and a < b} then find the domain of R ?

This question was previously asked in
Agniveer Vayu Science (Group X) 22nd March 2025 Memory-Based Paper
View all Airforce Group X Papers >
  1. {1, 2, 3, 4}
  2. {1, 2, 3, 4, 5}
  3. {1, 3, 4, 5}
  4. None of these

Answer (Detailed Solution Below)

Option 1 : {1, 2, 3, 4}
Free
General Knowledge for All Defence Exams (शूरवीर): Special Live Test
23.2 K Users
20 Questions 20 Marks 16 Mins

Detailed Solution

Download Solution PDF

Concept:

Domain of a Relation: Let R be a relation from set A to set B. Then, the set of all first components of the ordered pair belonging to relation R forms the domain of the relation R.

i.e Domain (R) = {a: (a, b) ∈ R}

Calculation:

Given: A = {1, 2, 3, 4, 5} , B = {1, 4, 5} and R = {(a, b): a ∈ A, b ∈ B and a < b}

Here, we have to find the domain of R.

⇒ R = {(1, 4), (1, 5), (2, 4) , (2, 5), (3, 4), (3, 5), (4, 5)}

As we know that, Domain (R) = {a: (a, b) ∈ R}

So, for the given relation R, we have

Domain (R) = {1, 2, 3, 4}

Latest Airforce Group X Updates

Last updated on Jul 11, 2025

->Indian Airforce Agniveer (02/2026) Online Form Link has been activated at the official portal. Interested candidates can apply between 11th July to 31st July 2025.

->The Examination will be held 25th September 2025 onwards.

-> Earlier, Indian Airforce Agniveer Group X 2025 Last date had been extended.

-> Candidates applied online from 7th to 2nd February 2025.

-> The online examination was conducted from 22nd March 2025 onwards.

-> The selection of the candidates will depend on three stages which are Phase 1 (Online Written Test), Phase 2 ( DV, Physical Fitness Test, Adaptability Test), and Phase 3 (Medical Examination).

-> The candidates who will qualify all the stages of selection process will be selected for the Air Force Group X posts & will receive a salary ranging of Rs. 30,000.

-> This is one of the most sought jobs. Candidates can also check the Airforce Group X Eligibility here.

Get Free Access Now
Hot Links: rummy teen patti teen patti master list teen patti party teen patti master new version master teen patti