a costumer comes in on a Tuesday on 1pm to order lunch. they tell you that they want to get the Tuesday lunch discount which is 20% off your entire bill. He also brought a coupon that is an additional 10% of the discount price if his food originally came to $18, what will be the final cost of the costumer's lunch. (Without tax or tip)

Discount 1
how much would you save?
how much would you pay.?
(New price)

The first discount is 20% off, so the customer would save:

20% of $18 = 0.2 x 18 = $3.60

The new price after the first discount would be:

$18 - $3.60 = $14.40

The second discount is an additional 10% off the discounted price, so the customer would save:

10% of $14.40 = 0.1 x 14.40 = $1.44

The final cost of the customer's lunch would be:

$14.40 - $1.44 = $12.96