6) \(\left(\frac{3}{25}-\frac{1}{20}\right)\cdot\frac{5}{14}\)

\[\left(\frac{3}{25}-\frac{1}{20}\right)\cdot\frac{5}{14}=\left(\frac{12}{100}-\frac{5}{100}\right)\cdot\frac{5}{14}\]

\[=\frac{7}{100}\cdot\frac{5}{14}=\frac{1}{40}\]

Ответ: \(\frac{1}{40}\)