Note: This problem closely resembles one of the supplemental examples in the video linked below.

Dan learns how to type. As time goes on$,$ Dan becomes more and more efficient at typing. Specifically, if $x$ represents the number of weeks since Dan started learning how to type, then Dan's word per minute $($WPM$)$ can be approximated by the function

$W(x)=\frac{200x}{4x+12}$

$($a$)$ What is Dan's WPM when Dan has learned typing for $2$ weeks?

$($Enter a numerical value. Do not include unit.$)$

$($b$)$ What will Dan's WPM be in the long run?

$($Enter a numerical value. Do not include unit.$)$