Answer:
There are multiple solutions:
3 oranges, 6 cookies
8 oranges, 3 cookies
11 oranges, 0 cookies
Explanation:
There are multiple solutions.
For the decimal 0.25, we know that either 3, 7 or 11 oranges were sold.
If 11 oranges were sold, they cost 0.75*11=8.25 dollars, and thus no cookies were sold.
If 8 oranges were sold, they cost 0.75*8=5.25 dollars, and thus 8.25-5.25=3 cookies were sold.
If 3 oranges were sold, they cost 0.75*3=2.25 dollars, and thus 8.25-2.25=6 cookies were sold.