First, we can determine the amount of the tax:
#t = b * 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 #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 * 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 #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#