My score: $\frac{4}{22}$ pts $(18\mathrm{.}18\%)$

The area of a circle increases at a rate of $5c\frac{m^2}{s}.$

a$.$ How fast is the radius changing when the radius is $3$ cm $?$

b$.$ How fast is the radius changing when the circumference is $2$ cm $?$

a$.$ When the radius is $3$ cm $,$ the radius is changing at a rate of $$ ve $$

$($Type an exact answer, using $$ as needed.$)$