Same chapter2 marksDifficulty: Easy
Distinguish between a finite and an infinite set, and between an empty set and a singleton set.
Sets
2 marksDifficulty: Easy
If n(A) = 20, n(B) = 28 and n(A ∩ B) = 8, find n(A ∪ B).
Original Khojo Papers practice question — not from a past board paper.
Answer
40
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
n(A ∪ B) = n(A) + n(B) − n(A ∩ B) = 20 + 28 − 8 = 40.
Related questions
From the same topic and chapter, at a similar level.
Same chapter2 marksDifficulty: Easy
How many subsets does a set with 5 elements have, and how many of them are proper subsets?
Sets
Same chapter3 marksDifficulty: Medium
If A = {1, 2, 3, 4} and B = {3, 4, 5, 6}, find A ∪ B, A ∩ B and A − B.
Sets
Same chapter3 marksDifficulty: Medium
In a class of 60 students, 35 play cricket, 28 play football and 12 play both. How many play neither?
Sets
Same chapter3 marksDifficulty: Medium
Define the power set and write the power set of A = {1, 2}.
Sets
Same chapter3 marksDifficulty: Medium
State De Morgan's laws for sets.
Sets