Help!

I need to program a toll simulation using an applet and the details are :

input : number of vehicles and type of vehicles( different vehicles have different toll rates) lets say i have 5 cars, 4 vans and 7 trucks and the charge for a car is 0.5, a van is 1.0 and a truck is 2.5

lets say i have 3 toll stations with 3 working times for each vehicle lets say 1s, 3s and 5s. every vehicle will go through the 3 tolls randomly.

output : sum of money received at each toll station.

any ideas on doing this using threading? thanks in advance.

Didnt cornedbee give you the formula to do this?