JEE Main 2025 — Permutation Combination Question with Solution
JEE Main 2025 (7 Apr Shift 1)
Question
For , let denote the set of all subsets of with no two consecutive numbers. For example , but . Then is equal to ________
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Show full solutionCorrect answer: 13
Correct answer
13
Step-by-step explanation
No. of subsets having elements such that no two are consecutive is
for , no. of ways
Subsets having no element
Subsets having exactly 1 element
Subsets having exactly 2 element
Subsets having exactly 3 element
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This is a previous-year question from JEE Main 2025, 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.