a)

$$\begin{gathered} 1\frac{3}{8}-3\frac{1}{2}\cdot \frac{1}{28}\cdot \frac{7}{10}=1\frac{3}{8}-\frac{{\cancel{7}}^1}{2}\cdot \frac{1}{{\cancel{28}}_4}\cdot \frac{7}{10}= \\ =1\frac{3}{8}-\frac{1}{2}\cdot \frac{1}{4}\cdot \frac{7}{10}=1\frac{3}{8}-\frac{1}{8}\cdot \frac{7}{10}= \\ =1\frac{3\cdot 10}{8\cdot 10}-\frac{7}{80}=1\frac{30}{80}-\frac{7}{80}=1\frac{23}{80} \end{gathered}$$

---

b)

$$\begin{gathered} 3\frac{3}{4}\cdot \frac{1}{4}+\frac{1}{8}:\frac{1}{4}=\frac{15}{4}\cdot \frac{1}{4}+\frac{1}{8_{:4}}\cdot \frac{4^{:4}}{1}= \\ =\frac{15}{16}+\frac{1}{2}\cdot \frac{1}{1}=\frac{15}{16}+\frac{1\cdot 8}{2\cdot 8}= \\ =\frac{15}{16}+\frac{8}{16}=\frac{23}{16}=1\frac{7}{16} \end{gathered}$$

---

c)

$$\begin{gathered} 3\frac{1}{5}:\frac{8}{25}-\frac{1}{4}:\frac{1}{3}=\frac{16^{:8}}{5_{:5}}\cdot \frac{25^{:5}}{8_{:8}}-\frac{1}{4}\cdot \frac{3}{1}= \\ =\frac{2}{1}\cdot \frac{5}{1}-\frac{3}{4}=\frac{10\cdot 4}{1\cdot 4}-\frac{3}{4}= \\ =\frac{40}{4}-\frac{3}{4}=\frac{37}{4}=9\frac{1}{4} \end{gathered}$$

---

d)

$$\begin{gathered} 3\frac{1}{2}-2\frac{1}{4}+4\frac{2}{5}:\frac{11}{25}=3\frac{1\cdot 2}{2\cdot 2}-2\frac{1}{4}+\frac{22^{:11}}{5_{:5}}\cdot \frac{25^{:5}}{11_{:11}}= \\ =3\frac{2}{4}-2\frac{1}{4}+\frac{2}{1}\cdot \frac{5}{1}=1\frac{1}{4}+\frac{10}{1}=1\frac{1}{4}+10=11\frac{1}{4} \end{gathered}$$