A construction working repairing a window tosses a tool to his partner across the street. The height of the tool above the ground is modelled by the quadratic function $h(t)=-5t^2+20t+25$, where $h(t)$ is in metres and $t$ is the time in seconds, after the toss. <br><br> QUESTION: How high above the ground is the window ?

Question

$\begin{array}{1 1} (a)\;45\\(b)\;35\\(c)\;25\\(d)\;20\end{array}$