Setting up proportions solve word problems

$\frac{80\ students}{18\ A's}=\ \frac{30\ students}{x\ A's}$

$\frac{x\ A's}{30\ students}=\ \frac{80\ students}{18\ A's}$

$\frac{30\ students}{x\ A's}=\ \frac{80\ students}{18\ A's}$

$\frac{30\ students}{80\ students}=\ \frac{18\ A's}{x\ A's}$

$\frac{4\ bunches}{25\ dollars}=\frac{x\ bunches}{10\ dollars}$

$\frac{4\ dollars}{10\ bunches}=\frac{x\ dollars}{25\ bunches}$

$\frac{4\ bunches}{25\ dollars}=\frac{10\ bunches}{x\ dollars}$

1.6 bunches

10 bunches

62.5 bunches

12 bunches