Answer:
The total price that he has to pay is $21.8.
Explanation:
Mr. O'Donnell goes to the store to buy a shirt. The shirt is $20, but he also has to pay a 9% tax.
First you convert the sales tax percentage to its decimal form: in this case 9% becomes 0.09.
To calculate the cost of the tax, the following multiplication must be performed:
cost of product or service* sales tax (in decimal form) = total sales tax
In this case:
$20*0.09= $1.8
Finally, you must add the value of the total sales tax to the cost of the product or service to obtain the total cost. In this case:
$20 + $1.8= $21.8
So, the total price that he has to pay is $21.8.