Your state charges 5% sales tax on nonfood items. You're buying a light bulb for $3.00, cereal for

$2.50, and an orange for $.50. What will be the grand total of your bill?

We first add the tax to the non-food items. We have ($3.00+$.50) * 1.05 = ($3.50) * 1.05=$3.675 (Which can be rounded up to $3.68, since we can't have a fraction of a cent).

Now, we add the cost of the food to $3.68. As a result, we have $3.68+$2.50=$6.18 as the total bill.