The problem tells us that the 5% sales tax is only charged for non-food items. For the three items purchased, only one is non-food which is the light bulb. The cost of the light bulb is $3.00. In order to find the total after adding 5% sales tax, we can take the cost and multiply by 1.05, which is the original cost plus the additional 5%. 3 x 1.05 = 3.15. To find the total bill, you need to add the cost of the light bulb, after tax, plus the cost of cereal and an orange: 3.15 + 2.50 + 0.5 = $6.15.
