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Saturday, 31 October

JEE Main 2024 · MathsMultiple choiceSingle correctEasyCalculation

JEE Main 8 April 2024, Shift 2, Maths Q19

Question 19 of 90 in this shift, Maths question 19 of 30, Section A.

There are three bags X, Y and Z. Bag X contains 5 one-rupee coins and 4 five-rupee coins; Bag Y contains 4 one-rupee coins and 5 five-rupee coins and Bag Z contains 3 one-rupee coins and 6 five-rupee coins. A bag is selected at random and a coin drawn from it at random is found to be a one-rupee coin. Then the probability, that it came from bag Y, is :
  1. (1)512\frac{5}{12}
  2. (2)13\frac{1}{3}Official answer
  3. (3)14\frac{1}{4}
  4. (4)12\frac{1}{2}

Official answer

Option 2

NTA final key.

Chapter
Probability
Topic
Bayes' Theorem
Idea tested
Bayes' Theorem Application

Same idea in other shifts

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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.