In Java please

Ambulances are dispatached at a rate of one every 15(+-10) minutes in a large metropolitan area. Fifteen percent of the calls are false alarms, which require 12(+-2)minutes to complete.All other calls can be one of two kinds. The first kind are classified as serious. They constitue 15% of the non-false alarm calls and take 25(+-5) minutes to complete. The remaining calls take 20(+-10) minutes to complete. Assume that there are a very large number of available ambulances and that any number can be on call at any time. Simulate the system until 500 calls are completed.