Answer:
15 cookies
Explanation:
We have 20 cookies and we know that three quarters of them were burned. To find the number of cookies burned, divide the 20 cookies into 4 equal parts.
This will give you 4 parts of 5 cookies.
[5] + [5] + [5] + [5]
Then they tell us that 3 quarters were burned. This means that of these 4 parts [5] + [5] + [5] + [5], 3 were burned. Then take 3 of these parts and add them.
[5] + [5] + [5] = 15 cookies.
This is the same as multiplying:
