Calculating Percentages for Time Spent During Day, Week ...

A consulting engineer bought a fax machine. There will be no maintenance cost for the first year as it was sold with one year’s free maintenance. In the second year the maintenance is estimated at $20. In subsequent years the maintenance cost will increase $20 per year (that is, 3rd year maintenance will be $40, 4th year will be $60 and so ... ................
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