JEE Main 2023 · MathsMultiple choiceSingle correctMediumMulti-step

JEE Main 15 April 2023, Shift 1, Maths Q18

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

A bag contains 6 white and 4 black balls. A die is rolled once and the number of balls equal to the number obtained on the die are drawn from the bag at random. The probability that all the balls drawn are white is

(1) $\frac{1}{5}$ Official answer
(2) $\frac{11}{50}$
(3) $\frac{9}{50}$
(4) $\frac{1}{4}$

Official answer

Option 1

NTA final key.

Chapter: Probability
Topic: Bayes' Theorem
Idea tested: Theorem of Total Probability

Same idea in other shifts

Asked 3× in all

6 Apr 2026, Shift 1 · Q10A bag contains $(\mathrm{N}+1)$ coins $-$ N fair coins, and one coin with 'Head' on both sides. A coin is selected at random and tossed.…EasySingle correct
2 Sep 2020, Shift 1 · Q68Box I contains 30 cards numbered 1 to 30 and Box II contains 20 cards numbered 31 to 50. A box is selected at random and a card is drawn…MediumSingle correct

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.