CA Foundation · Quantitative Aptitude · Sets, Relations and Functions, Limits and Continuity
If A = {x : x is a prime number less than 12} and B = {x : x is an odd number less than 12, x > 0}, how many elements are in A − B?
The count is 1. The primes below 12 are 2, 3, 5, 7 and 11, while the odd numbers below 12 are 1, 3, 5, 7, 9 and 11. Removing the odd numbers from the primes leaves only 2.
- A0
- B1Correct
- C2
- D5
Explanation
A = {2, 3, 5, 7, 11} and B = {1, 3, 5, 7, 9, 11}. A − B contains elements of A not in B, which is only 2. So the count is 1.
Did you get it right without looking?
One question tells you little. A timed set on Sets, Relations and Functions, Limits and Continuity shows your real accuracy, how long you take and where you lose marks.
More Sets, Relations and Functions, Limits and Continuity questions
- Which of the following functions from R to R is both one-one (injective) and onto (surjective)?
- A relation R is defined from Set P = {1, 3, 5} to Set Q = {2, 4, 6} as R = {(1, 2), (1, 4), (3, 6), (5, 4)}. What is the domain of relation …
- A function is defined by f(x) = ax + b for x ≤ 1, f(x) = 7 for 1 < x < 3, and f(x) = 2ax − b for x ≥ 3. If f is continuous everywhere, what …
- Let f(x) = 2x + 3 and g(x) = x². What is the value of (g∘f)(2), that is g(f(2))?
- The function f(x) = px + 3 for x ≤ 2, and f(x) = x² + q for x > 2, is continuous everywhere. If p = 4, what is the value of q?
- If a set A has 5 elements, how many subsets of A are proper subsets that are also non-empty?