A Mechanical Engineer who was awarded a P450 00000 contract to install the machineries of an oil mill failed to finish the work on time As provided for in the contract, he has to pay a daily penalty equivalent to one-fourth of one per cent per day for the first 10 days and 05% per day for the next 10 days and one per cent per day for everyday thereafter If the total penalty was P60 75000, how many days was the completion of the contract delayed?