Adam celebrated his eighteenth birthday with friends at a chinese restaurant. the bill came to $287.69 without tax. the service was quite good so he decided to tip the waiter 20 percent. what is the amount of tip that adam and his friends should leave for the waiter? how much is the total bill (excluding tax)?

Total bill excluding tax is $287.69

the 20%
here's how I do it in restaurants
10% is just move decimal to left 1 place
20% is double of that
so
10% of 287.69 is 28.769
20% is double of that or 57.538 or rounded to 57.54

tip is $57.54
total bill (exclude tax) is $287.69

-by-step explanation: