JEE Main 2018MathematicsProbabilityMediumMCQ

JEE Main 2018 — Probability Question with Solution

JEE Main 2018 (16 Apr Online)

Question

Two different families A and B are blessed with equal number of children. There are 3 tickets to be distributed amongst the children of these families so that no child gets more than one ticket. If the probability that all the tickets go to the children of the family B is 112, then the number of children in each family is

Choose an option

Show full solutionCorrect option: B
Correct answer
B5

Step-by-step explanation

Let n number of children be there in each family.

112= nC3·3! 2nC3·3!

⇒ nC3 2nC3=112 

⇒nn-1n-22n2n-12n-2=112

⇒n-22n-1=13

⇒3n-6=2n-1

⇒n=5

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About this question

This is a previous-year question from JEE Main 2018, 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.