Anna enjoys dinner at a restaurant in Washington, D. C., where the sales tax on meals is 10%. She leaves a 15% tip on the price of her meal before the sales tax is added, and
the tax is calculated on the pre-tip amount. She spends a total of $27.50 for dinner.
What is the cost of her dinner without tax or tip?
Show or explain your work in the space below:
Can u plz help me with the model for the math problem plz?