5. Perkins, Inc. purchased inventory for $7,500 on trade credit terms of net 60 days. The selling firm offers Perkins a 0.35% discount if Perkins agrees to pay by via ACH. Perkins believes that ACH carries a 1-day float while a check carries a 3-day. Perkins' cost of capital is 8%. Perkin's cost of check is $1.05 and the ACH is $0.15. a. Should Perkins pay with ACH or check? Why? At what discount rate would Perkins be indifferent between checks and ACH? b