How much does one have to subtract from \( \frac{8}{5} \) to obtain \( \frac{5}{8} \)?
\( \frac{39}{64} \)
\( \frac{39}{40} \)
\( \frac{31}{40} \)
\( \frac{25}{64} \)
If \( \frac{3}{5} \) of a bottle is filled, what is the ratio of the filled part to the empty part of the bottle?