Answer:
There were 27 apples.
Explanation:
Set a ratio of bananas to apples like this:
bananas/apples = 2/3
Now you have 18 bananas. The number of apples is unknown, so use "a" for the number of apples.
bananas/apples = 18/a
The two ratios above are equal, so set them equal. That creates a proportion.
2/3 = 18/a
Now we solve for a by cross multiplying.
2a = 3 * 18
2a = 54
a = 27
Answer: There were 27 apples.