An $\frac{f}{2\mathrm{.}85}$ CCD camera has a $104$ mm focal length lens and can focus on objects from infinity to as near as $33\mathrm{.}5$ cm from the lens. Note: $"\frac{f}{2\mathrm{.}85}"$ means $"$an $f-$number of $2\mathrm{.}85."$

$($a$)$ Determine the camera's aperture diameter in mm$.$

$$ mm

Determine the minimum and maximum distances in cm from the CCD sensor over which the lens must be able to travel during focusing.

$($b$)$ minimum

$$ cm

$($c$)$ maximum

$$ cm