Question

Could you help me with this problem? I want to tip 20%.

Answer 1

Cost of the meal: $15

Sales tax rate: 6.6%

3.1

The sales tax is given by:

`\begin{gathered} \text{ Sales tax }=6.6\text{\% of the cost of the meal} \\ \\ \text{ Sales tax }=(6.6)/(100)\cdot15=\text{\$}0.99 \end{gathered}`

3.2

The cost after the tax is given by the sum of the original cost and the sales tax. If x is the original cost and y is the cost after sale tax:

`\begin{gathered} y=x+0.066x \\ \\ \therefore y=1.066x \end{gathered}`

3.3

If the tip represents between 15% and 20% of the original cost:

`\begin{gathered} \text{ min tip }=(15)/(100)\cdot15=\text{\$}2.25 \\ \\ \text{ max tip }=(20)/(100)\cdot15=\text{\$}3 \end{gathered}`

The tip I choose is $3 (20%)

3.4

Finally, for the total bill we add the cost after sale tax and the tip:

`\begin{gathered} \text{ Total bill }=15.99+3 \\ \\ \therefore\text{ Total bill }=\text{\$}18.99 \end{gathered}`