Final answer:
The entire meal will cost $41.14, including sales tax and tip.
Step-by-step explanation:
To calculate the entire cost of the meal, we need to consider the cost of the meals, the cost of the drinks, the sales tax, and the tip.
The cost of Abraham's meal is $12.99, and the cost of his mom's meal is $14.79. They each order a drink for $2.75.
The total cost for the meals is $12.99 + $14.79 = $27.78. The total cost for the drinks is $2.75 + $2.75 = $5.50.
Now, we need to calculate the sales tax, which is 7.5% of the total cost of the meals and drinks.
The sales tax amount is 7.5% of ($27.78 + $5.50) = 7.5% of $33.28 = $2.49.
Next, we need to calculate the tip, which is 15% of the total cost of the meals and drinks including the sales tax.
The tip amount is 15% of ($33.28 + $2.49) = 15% of $35.77 = $5.37.
Finally, to find the entire cost of the meal, we add the total cost of the meals and drinks, the sales tax, and the tip.
The entire meal will cost $33.28 + $2.49 + $5.37 = $41.14.