Sets & RelationseasyFree

Subsets of A×B with at Least Three Elements | JEE Sets

JEE Maths question with a full step-by-step solution.

Question
Let AA and BB be two sets containing four and two elements respectively. Then the number of subsets of the set A×BA \times B, each having at least three elements, is:
A219219correct
B256256
C275275
D510510
Solution
n(A×B)=4×2=8total subsets=28=256.n(A \times B) = 4 \times 2 = 8 \Rightarrow \text{total subsets} = 2^8 = 256.
Subtract subsets with fewer than 33 elements:
256(80)(81)(82)=2561828=219.256 - \binom{8}{0} - \binom{8}{1} - \binom{8}{2} = 256 - 1 - 8 - 28 = 219.
Correct answer: (1)
Still stuck on this question?Ask your doubt on WhatsApp
Similar questions

Solve more, learn faster

Sign up free to solve more JEE Maths questions and explore doMath — timed drills, mastery sprints, bookmarks, and chapter-wise progress tracking.