Answer:
Tip Total: $5.14
Total Pay (Bill + Tip): $30.85
Explanation:
Quick tip calculation for 15% tips:
If you're leaving the standard 15% tip, here's a quick and easy way to calculate it in your head, at the table in the restaurant, without embarassing yourself by scribbling all over the back of a receipt or getting out a calculator:
15% is 10% + 5% (or 0.15 = 0.1 + 0.05, dividing each percent by 100). Thinking about it this way is useful for two reasons. First, it's easy to multiply any number by 0.1; just move the decimal point left one digit. For example, 75.00 x 0.1 = 7.50, or 346.43 x 0.1 = 34.64 (close enough). Second, 5% is exactly half of 10%. So here's how this quick and easy method works:
Take the total cost of your meal, $25.71 and multiply it by 0.1 by sliding the decimal to the left one digit to get $2.57 (you can do this in your head at the table). $2.57 is 10% of your meal cost. But the proper tip to leave is 15% (you need to throw in another 5%).
The additional 5% is just half of the 10% amount. What is half of $2.57? About $1.29. (Finding half of a number is also something you can do in your head at the table.) So, the total tip to leave is the 10% amount PLUS the 5% amount (for a 15% tip) or $2.57 + $1.29 = $3.86 .
The general rule here is:
Find the number that results from sliding the decimal point of the meal's cost left one digit,
and add on another half of this number.
That's your tip!