Final answer:
To make 3 dozen cookies instead of 2 dozen, you need to adjust the amounts of each ingredient in the recipe proportionally. The correct amounts of sugar, salt, and coarse sugar needed for 3 dozen cookies are 1 7/8 cups, 3/4 teaspoon, and 1 1/8 cups respectively.
Step-by-step explanation:
To make 3 dozen cookies instead of 2 dozen, you need to adjust the amounts of each ingredient in the recipe proportionally. Here's how:
Since there are 2 dozen cookies in the original recipe and you want to make 3 dozen, you need to multiply the amounts of each ingredient by 3/2.
So, for the sugar, you would multiply 1 1/4 cups by 3/2, which gives you 1 7/8 cups. For the salt, you would multiply 1/2 teaspoon by 3/2, which gives you 3/4 teaspoon. And for the coarse sugar, you would multiply 3/4 cup by 3/2, which gives you 1 1/8 cups.
Therefore, the correct answer is:
A) 1 7/8 cups of sugar, 3/4 teaspoon of salt, 1 1/8 cups of coarse sugar