Please describe the method to getting the discount rate number in part (a) for the attached problem:

On December 1, Showcase Interiors purchased a shipment of furniture from Colonial House by paying $10,500 cash and issuing an installment note payable in the face amount of $28,800. The note is to be paid in 24 monthly installments of $1,200 each. Although the note makes no mention of an interest charge, the rate of interest usually charged to Showcase Interiors in such transactions is 1% percent per month. Instructions a. Compute the present value of the note payable, using a discount rate of 1,2 percent per month. b. Prepare the journal entries in the accounts of Showcase Interiors on: 1. December 1, to record the purchase of the furniture (debit Inventory)