Computer Science:

Let $E(n)$ represent the running time in seconds of a computer algorithm when the input size is $n$ items.

$($a$)$ What are the units of $n,E(n),$ and $E^{\text{'}}(n)?$

$($b$)$ Describe the practical meaning of $E^{\text{'}}(1000)=3.$

$($c$)$ Given $E^{\text{'}}(n)>0$ and what can you infer about the efficiency of the algorithm as the input size increases?

$($d$)$ Describe the units and practical meaning of $(E^{-1}{)}^{\text{'}}(2000)=0\mathrm{.}5.$