Answer:
The cost of total lunch is 1.18 y ( 1+ 0.0 x )
Explanation:
Given as :
The percentage of tip added tot he bill after tax = 18 %
Let the tax added to the bill = x % of total the lunch price
Let The total lunch cost = y
So, The cost of the lunch after tax = y + x % × y
I.e The cost of lunch after tax = y × ( 1 +x % )
Or. The bill of lunch after tax = y × ( 1 + 0.0 x )
Now the cost of lunch after tax and tip =18 % of y × ( 1 + 0.0 x ) + y × ( 1 + 0.0 x )
Or, the cost of lunch after tax and tip = y × ( 1 + 0.0 x ) (0.18 + 1 )
∴ The cost of lunch after tax and tip = y × ( 1 + 0.0 x ) × 1.18
Hence The cost of total lunch is 1.18 y ( 1+ 0.0 x ) Answer