Simplify :

$3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(2\dfrac{4}{5} - 1\dfrac{7}{10}\Big)\right\rbrace$

$\Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(2\dfrac{4}{5} - 1\dfrac{7}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{14}{5} - \dfrac{17}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{14 \times 2}{5 \times 2} - \dfrac{17}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{28}{10} - \dfrac{17}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{28 - 17}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(\dfrac{11}{10}\Big)\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace\dfrac{11}{8} \div \dfrac{11}{10}\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \left\lbrace\dfrac{11}{8} \times \dfrac{10}{11}\right\rbrace\\[1em] \Rightarrow 3\dfrac{7}{8} - \dfrac{10}{8}\\[1em] \Rightarrow \dfrac{31}{8} - \dfrac{10}{8}\\[1em] \Rightarrow \dfrac{31 - 10}{8}\\[1em] \Rightarrow \dfrac{21}{8}\\[1em] \Rightarrow 2\dfrac{5}{8}$

Hence, $3\dfrac{7}{8} - \left\lbrace1\dfrac{3}{8} \div \Big(2\dfrac{4}{5} - 1\dfrac{7}{10}\Big)\right\rbrace = 2\dfrac{5}{8}$.