\[ \begin{align*} \dfrac{5}{8} \times \dfrac{16}{25} \times \dfrac{10}{7} &= \dfrac{5\times 16\times 10}{8\times 25\times 7} \\ &= \dfrac{800}{1400} \\ &= \dfrac{4}{7} \end{align*} \] \[ \begin{align*} 4 \times \dfrac{7}{9} \times \dfrac{27}{28} &= \dfrac{4\times 7\times 27}{1\times 9\times 28} \\ &= \dfrac{756}{252} \\ &= 3 \end{align*} \] \[ \begin{align*} \dfrac{12}{15} \times \dfrac{25}{18} \times \dfrac{9}{10} &= \dfrac{12\times 25\times 9}{15\times 18\times 10} \\ &= \dfrac{2700}{2700} \\ &= 1 \end{align*} \] \[ \begin{align*} \dfrac{6}{11} \times 22 \times \dfrac{5}{12} &= \dfrac{6\times 22\times 5}{11\times 1\times 12} \\ &= \dfrac{660}{132} \\ &= 5 \end{align*} \]