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AMO 2025 Secondary 1 (Grade 7) Question 2

AMO · AMO 2025 Secondary 1 (Grade 7)

Question 2

At a local school, 70% of middle school students have a smartphone. Students are asked at random until one has a smartphone. What is the probability, as a percentage, that at least four students must be asked? Clarification: use independent trials, each with a 70% chance; the source does not specify a finite-population sampling model.

Question illustration
  1. 5.1%
  2. 3.2%
  3. 2.7%
  4. 1.8%