Compute \(C(5, 3)\), \(C(4, 2)\), and \(C(4, 3)\) and verify that formula (2.3) holds.

\[C(5, 3) = \binom{5}{3} = \frac{5 \cdot 4 \cdot 3}{3 \cdot 2 \cdot 1} = 10\]

\[C(4, 2) + C(4,3) = \binom{4}{2} + \binom{4}{3} = \frac{4 \cdot 3}{2 \cdot 1} + \frac{4 \cdot 3 \cdot 2}{3 \cdot 2 \cdot 1} = 6 + 4 = 10\]