JEE Main 2021 · MathsMultiple choiceSingle correctMediumApplication

JEE Main 26 August 2021, Shift 2, Maths Q78

Question 78 of 90 in this shift, Maths question 18 of 30, Section A.

A fair die is tossed until six is obtained on it. Let X be the number of required tosses, then the conditional probability

\mathrm{P}(\mathrm{X}\geq5\,|\,\mathrm{X}>2)

is :

(1) $\frac{11}{36}$
(2) $\frac{25}{36}$ Official answer
(3) $\frac{5}{6}$
(4) $\frac{125}{216}$

Official answer

Option 2

NTA final key.

Chapter: Probability
Topic: Conditional Probability
Idea tested: Conditional Probability Definition

Same idea in other shifts

Asked 5× in all

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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.