Answer
Piano:
$$\frac{1}{20} $$
Guitar:
$$\frac{1}{10} $$
Woodwinds:
$$\frac{1}{8}$$
Drums:
$$ \frac{1}{6}$$
Strings:
$$ \frac{1}{3}$$
Work Step by Step
We divide the number of the bass by the number of each of the other 5 instruments to find the 5 requested ratios. Doing this, we find:
Piano:
$$ =\frac{5}{100} \\ =\frac{1}{20} $$
Guitar:
$$ =\frac{5}{50} \\ =\frac{1}{10} $$
Woodwinds:
$$ =\frac{5}{40} \\ =\frac{1}{8}$$
Drums:
$$ =\frac{5}{30} \\ =\frac{1}{6}$$
Strings:
$$ =\frac{5}{15} \\ =\frac{1}{3}$$
