JEE Main 2012 — Permutation Combination Question with Solution
JEE Main 2012 (Offline)
Question
Let . The number of different ordered pairs that can be formed such that and is empty, is
Choose an option
Show full solutionCorrect option: B
Correct answer
B
Step-by-step explanation
Let , then we have following chances that
(1)
(2)
(3)
(4)
We require
Hence (2), (3), (4) are chances for '' to satisfy .
has chances for .
Hence for five elements of , the number of required chances is
Practice this on the real CBT interface
Solve this JEE Main question (and the rest of the Permutation Combination chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.
Solve interactively →About this question
This is a previous-year question from JEE Main 2012, covering the Permutation Combination chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.