It takes 3/4 cup of sugar to make 18 cookies. How many cookies can you make with 6 cups of sugar?

Let's think this one through....

If 3/4 cup makes 18 cookies, then each 1/4 of a cup must make 6 cookies.

Then, 1 cup must make 4 times as many =  24 cookies

Then 6 cups must make 6 times as many as 1 cup.

Then, 6 x 24 =  144 cookies !!!