Situation $2.$ A certain toll booth can handle on the average of one vehicle every $6sec.$ Morning pear period traffic volumes starts from $7$:$00$ AM to $8$:$30$ AM due to some reasons. Before $7$:$00$ AM$,$ two booths are open. At $7$:$30$ AM$,$ a third booth was opened until $8$:$30$ AM$.$

$\backslash$table$[[$Time Period,$15$ min. Volume,$\backslash$table$[[$Cumulative$],[$Volume$]]],[7$:$00-7$:$15,200,],[7$:$15-7$:$30,400,],[7$:$30-7$:$45,500,],[7$:$45-8$:$00,550,],[8$:$00-8$:$15,400,],[8$:$15-8$:$30,250,]]$

Determine the time at which the number of vehicles in queue is $150.$

Determine the max. queue and the time it occurs.

Determine the total delay in vehicle$-$hr$.$