of eight (8) consecutive  Normal working hours , which may be interrupted by a period of  hours not defined as  Normal working hours. If failures during the guarantee period are such as to make a  Product  unusable for an  uninterrupted period of more than one (1) calendar week, the contracting authority shall be  entitled to have the  Complex hardware product  replaced free of charge by the contractor.  If the aggregate unavailability of a  Product  during  Normal working hours  exceeds forty-eight  (48) hours, the contracting authority is entitled to terminate the part of the specific contract  relating to that  Product .  IV.3.5.1  Determination of the periodic rental/leasing to be paid  n times at the beginning  of each period for an investment of PV with no residual value FV at the end of the  n periods:  IV.3.5.2  Determination of the periodic rental/leasing to be paid n times at the beginning of  each period for an investment of PV with a residual value FV at the end of the n  periods:  IV.3.5.3  Determination of the periodic rental to be paid n times at the end of each period for an  investment of PV with no residual value FV at the end of the n periods:  IV.3.5.4  Determination of the periodic rental to be paid n times at the end of each period for an  investment of PV with a residual value FV at the end of the n periods :  Page 20 of 40  𝑃𝑀𝑇 = ( 𝑃𝑉 − 𝐹𝑉 ) 𝑖 (1 − 1 ( 1 + 𝑖 ) $_{𝑛}$) $_{+ 𝐹𝑉. 𝑖}$  𝑃𝑀𝑇 = 𝑃𝑉 𝑖 (1 − 1 ( 1 + 𝑖 ) $_{𝑛}$) 𝑃𝑀𝑇 = ( 𝑃𝑉 − 𝐹𝑉 ) 𝑖 (1 − 1 ( 1 + 𝑖 ) $_{𝑛}$) 1 1 + 𝑖 + 𝐹𝑉 𝑖 $_{1 + 𝑖}$  𝑃𝑀𝑇 = 𝑃𝑉 𝑖 (1 − 1 ( 1 + 𝑖 ) $_{𝑛}$) 1 $_{1 + 𝑖}$  IV.3.5.  Leasing and Rental formula 