please help me, will mark you brainliest !!

Answer:
13
Step-by-step explanation:
Divide the total amount he paid by the amount of mugs he bought to find out how much each mug cost.
54 ÷ 6 = $9
Each mug is nine dollars, INCLUDING THE SALE which is $4 off.
Add $4 to $9 to find the regular price
$4 + $9 = 13
Answer:
The awnser should be $11
Step-by-step explanation:
You would need to divide the total price Luis pays, $51 by the amount he got 3. From there you would get 17=p but you would have to subtract it by the sale which was $6 and you get $11.