You are purchasing four items and you want to calculate the tax. the items cost 2.50, 8.75, 3.00, and 10.25. the tax rate is 6%. how much is the tax?

In the question it is already given that 4 items are being purchased and their individual rates are also given. the percentage of tax that needs to be paid is also given. To find the total amount of tax that has to be paid, you can either calculate the taxes on individual items and then add them or you can add the total amount required for the 4 items and then calculate the tax. Both will yield the same result but the second process is easier.
Cost of all the 4 items purchased = (2.50 + 8.75 + 3.00 + 10.25)
                                                       = 24.50
Percentage of tax that needs to be paid = 6%
Amount of tax that needs to be paid = (6/100) * 24.50
                                                           = 147/100
                                                           = 1.47
So the amount of tax that needs to be paid is 1.47.