Andrew pays $15 for a haircut . He leaves a 20% tip. What is the total amount andrew pays for the haircut, including the tip?

$18.00

Step-by-step explanation:

Start by working out 10%, that's easy:

15 ÷ 10 = 1.5

That means a 10% tip would be $1.50, so a 20% tip would be twice that amount:

1.50 x 2 = 3

A 20% tip is $3.00, and added on to the original $15.00, the total is $18.00

your answer would be 10x - 1