21.A firm considering the installation of an automatic data processing unit to handle some of its accounting operations. Machines for that purpose may be for P20,000, or may be leased for P8,000 for...

21.A firm considering the installation of an automatic data processing unit to handle some of its accounting operations. Machines for that purpose may be for P20,000, or may be leased for P8,000 for the 1st year and P1,000 less every year now and then until the end of the 4th year. If money is worth 15%, is it advisable to rent or buy the machine. *In written solution please