JEE Main 2021MathematicsProbabilityMediumMCQ

JEE Main 2021 — Probability Question with Solution

JEE Main 2021 (16 Mar Shift 2)

Question

Let A denote the event that a 6-digit integer formed by 0,1,2,3,4,5,6 without repetitions, be divisible by 3 . Then probability of event A is equal to :

Choose an option

Show full solutionCorrect option: B
Correct answer
B49

Step-by-step explanation

Total cases : 6·6·5·4·3·2

ns=6·6 !

Favourable cases :

Number divisible by 3≡ Sum of digits must be divisible by 3

Case-I

1,2,3,4,5,6

Number of ways =6 !

Case-II

0,1,2,4,5,6

Number of ways =5·5 !

Case-III

0,1,2,3,4,5

Number of ways =5·5 !

n( favourable )=6 !+2·5·5 !

P=6 !+2·5·5 !6·6 !=49

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About this question

This is a previous-year question from JEE Main 2021, covering the Probability 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.