A pedestrian sanitizing tunnel has a price of $7672.42 plus IVA in cash and if it were on credit it would charge a compound interest rate of 16.20% per year with bimonthly capitalization payable in 20 months. a) (1/2 point) Calculate the total amount to be paid for the pedestrian sanitizing tunnel on credit. b) (1 point) If, due to a fortuitous increase in sales, it is decided that the upon reaching 60% of the total time originally agreed. Under these conditions how much must be paid for the sanitizing tunnel and how much is the discount granted by advance payment (Calculate by difference and corroborate the result by formula of trade compound discount) c) (1 point) What would be the period to which the debt should be covered so that the payment of the tunnel is $9900.82 d) (1/2 point) But what would happen if due to force majeure it is necessary to request a extension of payment for 150 additional days to the time agreed to settle the debt under these new conditions what would be the total amount to be covered by the machinery.