12.2.46 Number theory
Condition: How many integers are in the sequence \( \frac{1 \cdot a}{b}, \frac{2 \cdot a}{b}, \ldots, \frac{b \cdot a}{b} \), where \( a, b \in \mathbb{N} \).
A huge number of interesting olympiad problems in number theory, and its various sections.