The correct answer for that is y=4
Answer: 
Step-by-step explanation:
By definition, the volume of a rectangular prism can be calculated with the following formula:

Where "l" is the length, "w" is the width and "h" is the height of the rectangular prism.
In this case, you can identify that the length, the width and the height of this rectangular prism given in the exercise, are:

Then, knowing its dimensions, you can substitute them into the formula:

Finally, evaluating, you get that the volume of that rectangular prism is:

First generation: 3
Second generation:

Third generation:

Fourth generation:

And so on. The general formula for the

th generation is

. So by the 15th generation, you should expect around

geese.
Technically you would add two people to oatmeal, but that is just me.