Answer:
6 (or 6.15, depends))
Step-by-step explanation:
We can write 3 1/4 as 3,25, as 1/4=0.25. This will make our calculation easier.
Now, if 3.25 cups gives us 1 batch, and we have 20 cups, we just need to get how many times the number 3.25 enters on 20. This means we just need to divide 20 by 3.25:
20 / 3.25 = 6.15 (aprox)
So, with 20 cups she can bake 6.15 batches. If you can't have decimal numbers (because there are not decimal oh partial batches, for example), your answer is 6. This last point will depend on the statement of your exercise.
Another way of doing it is simply sum 3.25 until you arrive to 20:
3.25 + 3.25 = 6.5
3.25 + 3.25 + 3.25 = 9.75
...
3.25 + 3.25 + 3.25 + 3.25 + 3.25 + 3.25 = 19.5
So, with 19.5 cups you get 6 batches.
