An old equal$-$tangent crest vertical curve was designed with a PVI at station $117$

$+45$ and elevation of $960ft.,$ and a PVC at station $110+85$ and elevation of $927ft.$ If the highest point

on the curve is at station $117+65,$ what is the maximum safe design speed for this curve? $($explore and

report your answer in $5mph$ increment$)[$hint: Use design tables. But this time, find the speed based on $K]$