a) $$ \frac{7}{15} \cdot 5 = \frac{7 \cdot 5}{15} = \frac{7 \cdot 1}{3} = \frac{7}{3} = 2\frac{1}{3} $$;
б) $$ 24 \cdot \frac{11}{48} = \frac{24 \cdot 11}{48} = \frac{1 \cdot 11}{2} = \frac{11}{2} = 5\frac{1}{2} $$;
в) $$ \frac{5}{18} \cdot 12 = \frac{5 \cdot 12}{18} = \frac{5 \cdot 2}{3} = \frac{10}{3} = 3\frac{1}{3} $$;
г) $$ 6 \cdot 3\frac{5}{6} = 6 \cdot \frac{3 \cdot 6 + 5}{6} = 6 \cdot \frac{18 + 5}{6} = 6 \cdot \frac{23}{6} = 23 $$.