Answer:
The tax rate is not needed
Total bill cost = $13
Step-by-step explanatio
Given that :
Tip left = 2.60
Tax = 5%
Tip left = 20% of after tax cost:
To calculate the total bill amount, we do not need information about the tax rate.
Since the total amount paid = after tax amount
Tip left = 2.60 is equal to 20% the after tax cost
Let after tax amount = t
Then,
20% of t = 2.60
(20/100) * t = 2.60
0.2t = 2.60
t = 2.60/0.2
t = 13
Hence, total bill is $13