# A restaurant bill comes to $28.35. How do you find the total cost if the tax is 6.25% and a 20% tip is left on the amount before tax? ##### 1 Answer Aug 15, 2017 See a solution process below: #### Explanation: First, we can determine the amount of the tax: $t = b \cdot r$Where: $t$is the amount of the tax. $b$is the amount of the bill -$28.35 for this problem.

$r$ is the tax rate. 6.25% for this problem. Percent or % means per 100 or out of 100. We can write 6.25% as $\frac{6.25}{100}$

Substituting gives:

t = $28.35 * 6.25/100 t = ($177.1875)/100

t = $1.771875 t =$1.77

Next, we can determine the amount of the tip:

$p = b \cdot g$

Where:

$p$ is the amount of the tip.

$b$ is the amount of the bill - $28.35 for this problem. $g$is the gratuity rate. 20% for this problem. Percent or % means per 100 or out of 100. We can write 20% as $\frac{20}{100}$Substituting gives: p =$28.35 * 20/100

p = ($567.00)/100 p =$5.67

Now, we can add the amount of the bill, the tax and tip amounts to find the total cost:

$28.35 +$1.77 + $5.67 =$35.79