№14. \(\dfrac{\frac1{35}-\frac1{60}}{\frac1{21}}\)

\(\frac1{35}-\frac1{60}=\frac{60-35}{2100}=\frac{25}{2100}=\frac1{84}\).

\(\frac{1}{84}:\frac1{21}=\frac{21}{84}=\frac14\).

Ответ: \(\frac14\).