\(=\dfrac{1}{5}\left(\dfrac{19}{16}-\dfrac{1}{5}-\dfrac{1}{15}\right)=\dfrac{1}{5}\cdot\dfrac{221}{240}=\dfrac{221}{1200}\)
\(\dfrac{1}{5}\times\dfrac{19}{16}-\dfrac{1}{5}\times\dfrac{3}{15}-\dfrac{1}{5}\times\dfrac{1}{15}\)
\(=\dfrac{1}{5}\times\left(\dfrac{19}{16}-\dfrac{3}{15}-\dfrac{1}{15}\right)\)
\(=\dfrac{1}{5}\times\left(\dfrac{19\times15}{16\times15}-\dfrac{3\times16}{15\times16}-\dfrac{1\times16}{15\times16}\right)\)
\(=\dfrac{1}{5}\times\left(\dfrac{285}{240}-\dfrac{48}{240}-\dfrac{16}{240}\right)\)
\(=\dfrac{1}{5}\times\dfrac{221}{240}\)
\(=\dfrac{221}{1200}\)