No about a computer cartridge for $28.50 sales tax on the cartridge was 6.5% what was the total amount that Noah paid for the cartridge

To calculate sales tax's addition in the items price, convert the percentage into a decimal. For 6.5%, it become. 065.

Multiple the cost of the item by the sales tax.

28.50 *.065 = 1.85

This gives you the amount * added onto * the price of the item. So add this value to the initial price for the total cost.

28.50 + 1.85 = 30.35

To make this simpler, you can multiply the initial price by (1 + sales tax decimal), or 1+.065, which is 1.065.

28.50 * 1.065 = 30.35

Whichever way you chose works!