Hi!
Lets use a ratio. the recipe calls for 2 cups, for every pie, which is one pie.
So the ratio is 2:1
Now, lets look at the possible answers.
A, has the ratio 12:6. We need to use the ratio 2:1 to make sure this is correct. 2 x 6 = 12, and 12 ÷ 6 = 2, so A is a possibility.
B, has the ratio 8:4. Again, we check with the first ratio 2:1. 2 x 8 = 16, and 16 ÷ 4 = 4, so because the first equation did NOT equal 4, B is not a possibility.
C, has the ratio of 1:2. Because its TWO cups for ONE pie, it wouldn't be correct, so C is not a possibility as well.
D, has the ratio of 9:8. Again, we need to check if its correct using the original ratio of 2:1. 2 x 9 = 18, and 18 ÷ 2 = 2. The ratios do not match, therefore D is not a possibility at all as well.
So, Your Answer Is: A, 12 cups of flour are needed for 6 pies. Also know as the ratio, 12:6
(Here's a tip. When using ratios, use the original ratio to help you out. If when you multiply it doesn't equal the 2nd ratio (as in, 0:6 ⇇⇇ that one right there), and then you divide and it equals the first ratio (as in, this one right here ⇉⇉0:6), it still incorrect.... if all of that made sense)
Hope this helps!
~~~PicklePoppers~~~