Question

Peter wanted to leave a 15% tip. He thought to himself that 15% = 10% plus half of 10%. Which of the following equations will help Peter estimate the 15% tip on a $48.00 bill correctly?

A. $4.80 + $2.40 = $7.20
B. $4.80 + $4.80 = $9.60
C. $4.80 + $0.48 = $5.28
D. $2.40 + $2.40 = $4.80​

Answer 1

A. $4.80 + $2.40 = $7.20

Explanation:

10% is the same as 10/100 or 1/10. To find 10% of a number, move the decimal point one place to the left.

10% of $48 is $4.80

Now he needs 5% of $48 which is half of 10% of $48, so 5% of $48 is $2.40.

$4.80 + $2.40 = $7.20

Answer: A. $4.80 + $2.40 = $7.20