Problem $18-5($Algo$)$

A small town with one hospital has $2$ ambulances to supply ambulance service. Requests for ambulances during nonholiday weekenc average $0\mathrm{.}40$ per hour and tend to be Poisson$-$distributed. Travel and assistance time averages $1\mathrm{.}00$ hours per call and follows an exponential distribution Use Table $18\mathrm{.}4.$

a$.$ Find system utilization. $($Roundyour answer to the nearest whole percent.$)$