On Monday a town received $\displaystyle{5}\frac{{1}}{{2}}\usepackage{cmbright}\Huge\$ inches of snow. On Tuesday $\displaystyle{8}\frac{{3}}{{4}}\usepackage{cmbright}\Huge\$ inches of snow fell, and on Wednesday another $\displaystyle{6}\frac{{7}}{{8}}\usepackage{cmbright}\Huge\$ inches covered the town. What was the total amount of snowfall for the three days?

The answer should be written as a proper mixed number and should be simplified, if possible.