Tokens numbered 1 to 25: Draw one token uniformly at random. What is the probability the number is divisible by both 2 and 3?

Difficulty: Easy

Correct Answer: 4/25

Explanation:

Introduction / Context:Divisibility by both 2 and 3 means divisibility by 6. Count multiples of 6 up to 25 and divide by total tokens.

Given Data / Assumptions:Numbers: 1,…,25; uniform random draw.

Concept / Approach:Use floor division to count: ⌊25/6⌋ = 4.

Step-by-Step Solution:

Multiples of 6: 6, 12, 18, 24 (four numbers)Probability = 4/25

Why Other Options Are Wrong:7/25 or 9/25 overcount; 2/25 undercounts.

Common Pitfalls:Forgetting that 0 is not in the set; miscounting multiples.

Final Answer:4/25

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