$11\div120=\frac{11}{120}$(副/分)
$7\div80=\frac{7}{80}$(副/分)
$6\div60=\frac{1}{10}$(副/分)
$\frac{11}{120}=\frac{22}{240},$$\frac{7}{80}=\frac{21}{240},$$\frac{1}{10}=\frac{24}{240}$
因为$\frac{24}{240}>\frac{22}{240}>\frac{21}{240},$所以$\frac{1}{10}>\frac{11}{120}>\frac{7}{80}$
丙写得最快