JEE Main 2024 · MathsNumerical answerNumerical valueMediumCalculation

JEE Main 27 January 2024, Shift 1, Maths Q29

Question 29 of 90 in this shift, Maths question 29 of 30, Section B.

A fair die is tossed repeatedly until a six is obtained. Let X denote the number of tosses required and let

a=P(X=3)

b=P(X\geq3)

and

c=P(X\geq6\,|\,X>3)

. Then

\dfrac{b+c}{a}

is equal to ________.

Official answer

NTA final key.

Chapter: Probability
Topic: Conditional Probability
Idea tested: Memoryless Property in Discrete Trials

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.