GATE DA 2025 Q45: 100 dice: probability that at least one shows 1
- Probability and Statistics
- 2 marks
- MCQ
- −2/3 if wrong
Question
A random experiment consists of throwing 100 fair dice, each die having six faces numbered 1 to 6. An event represents the set of all outcomes where at least one of the dice shows a 1. Then,
Try it: multiple choice: exactly one correct option
Wrong answer costs 2/3 mark in GATE.
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Answer: C (official GATE 2025 final answer key)
Concept used: Complement rule for "at least one" events with independent trials.
First step: The complement is "no die shows 1". Each die avoids 1 with probability , independently.
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Source: official GATE 2025 DA question paper and final answer key, organised by IIT Roorkee. Question paper · Answer key
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