Answer
$r_A=31.8~mm$
$r_B=31.8~mm$
$n=1.90~canisters/min$
Work Step by Step
We can determine the required radius and the number of canisters as follows:
As $l=2\pi r_A$
$\implies 200=2\pi r_A$
This can be rearranged as:
$r_A=\frac{200}{2\pi}=31.8309mm$
Similarly, $r_B=\frac{200}{2\pi}$
$\implies r_B=31.8309mm$
Now the number of the canisters can be calculated as
$n=\frac{l}{200}$
$\implies n=\frac{\theta_B r_B}{200}$
We plug in the known values to obtain:
$n=\frac{12\times 31.8909}{200}$
$\implies n=1.90~canisters/min$
