A shady restaurant is charging customers gratuities after taxes without them being aware. If my total bill was $140, the sales tax in my city is 10%, I ordered a NY Striploin for $80, and I ordered a glass of wine for $10, how much did they charge me for gratuities? Let's be accurate as possible.
The total bill before taxes or gratuities was $80 for the steak + $10 for the wine = $80 + $10 = $90. If the tax is 10%, then the taxes paid were $90 * 10% = $9. That means that the total bill before gratuities was $90 + $9 = $99. If the final bill was $140, then you were charged $140 - $99 = $41 for gratuities.
The answer: 41.