60 is a common denominator, but not the least common denominator for the fractions. The least common multiple of 10 and 6 is 30, so rewrite both fractions with a denominator of 30. The correct answer is $\displaystyle\frac{{21}}{{30}}\usepackage{cmbright}\Huge\$ and $\displaystyle\frac{{5}}{{30}}\usepackage{cmbright}\Huge\$ .