[tex]\frac{3}{10}+\frac{7}{100}=\frac{3\times10}{10\times10}+\frac{7}{100}=\frac{30}{100}+\frac{7}{100}=\frac{30+7}{100}=\boxed{\frac{37}{100}}\leftarrow answer \boxed{B}\\\\other\ method:\\\\\frac{3}{10}=0.3\ and\ \frac{7}{100}=0.07\\\\therefore\\\\\frac{3}{10}+\frac{7}{100}=0.3+0.07=0.37=\boxed{\frac{37}{100}}[/tex]
