Please help solve in excel

A cosmopolitan area was deciding what form of security to use in its subway systems. The city ultimately decided to use metal detectors at the entrance of the subway, but it still must hire security personnel to patrol the area. The town currently uses both city police officers (P) and privately contracted security guards (G). The annual cost of one police officer is $65,000 in wages and benefits, while security guards only cost the city $35,000 per year on average. Each security guard reduces the number of muggings and violent crimes by 2 annually and deters 25 free riders. However, because of their focus on more serious offenses, a police officer only deters 15 free riders annually, but their presence prevents an estimated 6 muggings and violent crimes annually. The city must decrease muggings and violent crime by 250 incidents and reduce the number of free riders by 1,000. The town must have at least 12 police officers dedicated to patrolling subways, and because of a previously existing contract, they must employ at least 20 security guards. The citys objective is to meet these constraints with the least cost combination. How many city police officers and privately contracted security guards should the city hire?