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Friday, 9 October

JEE Main 2021 · MathsMultiple choiceSingle correctMediumMulti-step

JEE Main 25 July 2021, Shift 1, Maths Q74

Question 74 of 90 in this shift, Maths question 14 of 30, Section A.

Let 9 distinct balls be distributed among 4 boxes, B1B_1, B2B_2, B3B_3 and B4B_4. If the probability that B3B_3 contains exactly 3 balls is k(34)9k\left(\frac{3}{4}\right)^9 then k lies in the set :
  1. (1){x∈R:∣x−1∣<1}\{x\in\mathbf{R}:|x-1|<1\}
  2. (2){x∈R:∣x−2∣≤1}\{x\in\mathbf{R}:|x-2|\le1\}
  3. (3){x∈R:∣x−3∣<1}\{x\in\mathbf{R}:|x-3|<1\}Official answer
  4. (4){x∈R:∣x−5∣≤1}\{x\in\mathbf{R}:|x-5|\le1\}

Official answer

Option 3

NTA final key.

Chapter
Probability
Topic
No close match in our taxonomy
Idea tested
No close match in our taxonomy

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 42 of the 174 JEE Main shifts held from 2017 to 2026.