\(\frac{5}{16} \cdot \frac{12}{25} = \frac{5 \cdot 12}{16 \cdot 25} = \frac{5 \cdot (3 \cdot 4)}{(4 \cdot 4) \cdot (5 \cdot 5)} = \frac{3}{4 \cdot 5} = \frac{3}{20}\)
\(1 \frac{1}{3} \cdot 1 \frac{1}{8} = \frac{1 \cdot 3 + 1}{3} \cdot \frac{1 \cdot 8 + 1}{8} = \frac{4}{3} \cdot \frac{9}{8} = \frac{4 \cdot 9}{3 \cdot 8} = \frac{(4 \cdot 3) \cdot 3}{3 \cdot (2 \cdot 4)} = \frac{3}{2} = 1 \frac{1}{2}\)
\(3 \frac{3}{5} \cdot 1 \frac{11}{24} = \frac{3 \cdot 5 + 3}{5} \cdot \frac{1 \cdot 24 + 11}{24} = \frac{18}{5} \cdot \frac{35}{24} = \frac{18 \cdot 35}{5 \cdot 24} = \frac{(6 \cdot 3) \cdot (5 \cdot 7)}{5 \cdot (6 \cdot 4)} = \frac{3 \cdot 7}{4} = \frac{21}{4} = 5 \frac{1}{4}\)
\(6 \cdot 4 \frac{5}{12} = 6 \cdot \frac{4 \cdot 12 + 5}{12} = 6 \cdot \frac{48 + 5}{12} = 6 \cdot \frac{53}{12} = \frac{6 \cdot 53}{12} = \frac{53}{2} = 26 \frac{1}{2}\)
Ответ: а) ; б) ; в) ; г) .