JEE Main 2023 · MathsMultiple choiceSingle correctEasyCalculation

JEE Main 8 April 2023, Shift 1, Maths Q18

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

In a bolt factory, machines

A

B

and

C

manufacture respectively 20%, 30% and 50% of the total bolts. Of their output 3, 4 and 2 percent are respectively defective bolts. A bolt is drawn at random from the product. If the bolt drawn is found the defective, then the probability that it is manufactured by the machine

C

(1) $\frac{2}{7}$
(2) $\frac{5}{14}$ Official answer
(3) $\frac{3}{7}$
(4) $\frac{9}{28}$

Official answer

Option 2

NTA final key.

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

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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.