Divisible by 2 or 3

What this basic counting-and-probability question tests

This is a straightforward probability question that assesses whether you can correctly apply the inclusion-exclusion principle to count outcomes in a finite set. It is the kind of warm-up problem used to establish baseline comfort with set logic and discrete probability before moving to harder material.

The core skill is identifying how many integers in a range satisfy a compound condition (divisible by 2 or 3), which requires careful handling of overlap. Candidates who rush often double-count the intersection and arrive at the wrong answer. The cleanest approach is to count each subset separately, subtract the overlap once, and divide by the total.

• Inclusion-exclusion principle
• Divisibility and modular arithmetic
• Uniform discrete probability