Answer:
The total cost is 26.6 dollars
Step-by-step explanation:
Given
The total bill of the breakfast = $ 21.60
Sales tax = 7% of the total bill value
Total bill after adding the 7% sales tax
$ 21.60 + 7% of $ 21.60
[tex]21.60 + \frac{7}{100} * 21.60\\21.60 + 1.512\\23.112[/tex]dollars
After adding 15% of the tip values to the payable amount of $ 23.112, the total bill becomes
$ 23.112 + 15% of $ 23.112
[tex]23.112 + 3.4668 = 26.5788[/tex]
The total cost is 26.6 dollars