A geometric progression is also known as a geometric sequence.
Here is a video explaining how you find the n term value.
https://youtu.be/pwUdYEwT9kY
Hope this helps!

We will find the volume of each rectangular prism separately.
<h3>Top Figure</h3>



<h3>Bottom Figure</h3>



<h3>Adding Together</h3>


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➷ You are finding how many halves fit into 12
As there are 2 halves in 1, you would just need to double the value
Multiply by the denominator:
12 x 2 = 24
It is 24
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➶ Hope This Helps You!
➶ Good Luck (:
➶ Have A Great Day ^-^
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The average would be the total amount divided by the 2 groups, so the answer would be 37.5 years old.