Answer:
14 batches
Explanation:
If 1 sack of flour = 21 cups, and 1 batch of cookies need 3 cups, all you have to do is find out how many batches can be made with 1 sack and double the number:
3 × _ = 21
21 ÷ 3 = 7
7 × 2 = 14
You can make 14 batches of cookies with 2 sacks of flour.
Hope this helped.