Lets convert 3 3/4 into improper fraction first.
[tex]3\frac{3}{4} = \frac{3 \times 4 + 3}{4} \\ = \frac{15}{4} [/tex]
[tex] \frac{3\frac{3}{4} }{ \frac{2}{5} } \\ = \frac{15}{4} \div \frac{2}{5} \\ = \frac{15}{4} \times \frac{5}{2} \\ = \frac{75}{6} \\ = \frac{25}{2} \: or12 \frac{1}{2} or \: 12.5[/tex]