Question

A restaurant bill comes to $\mathrm{\$}28.35$. How do you find the total cost if the tax is $$6.25\mathrm{\%}$$ and a $$20\mathrm{\%}$$ tips is left on the amount before tax?

Answer 1

Hint: In this problem, we have to find the total cost. We are given the cost in a restaurant bill, tax percent and tips percent. We can first find the exact amount from the given tax percent and the given tips percent, from formulas. We can then add the cost in the bill and the tax amount and tip amount to find the total cost.

Complete step-by-step solution:
We know that the given data are,
The amount in the restaurant bill is $\mathrm{\$}23.35$.
The tax is $$6.25\mathrm{\%}$$ and tips are $$20\mathrm{\%}$$.
We can now find the exact amount of the tax and the tips, which is given in percentage.
We can use the formula,
$$\text{Tax = Bill amount }\times \text{ Tax rate}$$
We know that the bill amount is $\mathrm{\$}28.35$ and tax rate is $$6.25\mathrm{\%}$$. We can substitute these values in above formula, we get
$$\begin{array}{rl}& \Rightarrow \text{Tax}=28.35\times {\displaystyle \frac{6.25}{100}}\because 6.25\mathrm{\%}={\displaystyle \frac{6.25}{100}}\\ & \Rightarrow \text{Tax}={\displaystyle \frac{177.1875}{100}}\\ & \Rightarrow \text{Tax}=1.77\end{array}$$
The tax amount is $\mathrm{\$}1.77$.
Now we can find the tips amount from the formula,
 $$\text{Tips = Bill amount }\times \text{ Gratuity rate}$$
We know that the bill amount is $\mathrm{\$}28.35$ and the gratuity rate is $$20\mathrm{\%}$$. We can substitute these values in above formula, we get
$$\begin{array}{rl}& \Rightarrow \text{Tip amount}=28.35\times {\displaystyle \frac{20}{100}}\because 20\mathrm{\%}={\displaystyle \frac{20}{100}}\\ & \Rightarrow \text{Tip amount}={\displaystyle \frac{567.00}{100}}\\ & \Rightarrow \text{Tip amount}=5.67\end{array}$$
The tip amount is $\mathrm{\$}5.67$.
We can now add the bill amount, tax amount and the tip amount to get the total cost, we get
The total cost $$=28.35+1.77+5.67=35.79$$ .
Therefore, the total cost is $\mathrm{\$}35.79$.

Note: Students make mistakes while converting a percentage into fraction form. We should remember that percent means per 100 or out of hundred. We should also know that the total cost is the addition of the given bill amount, tax amount and the tip amount.