<u><em>Answer:</em></u>
D. 272 poles
<u><em>Explanation:</em></u>
<u>We are given that:</u>
The top layer has 20 poles, the next down one has 24 poles and the third one has 28 poles
<u>We can note that</u> each layer has 4 poles more that the one above it
<u>Based on this, we can get the number of poles in each layer as follows:</u>
Top layer has 20 poles
Second one has 20 + 4 = 24 poles
Third one has 24 + 4 = 28 poles
Fourth one has 28 + 4 = 32 poles
Fifth one has 32 + 4 = 36 poles
Sixth one has 36 + 4 = 40 poles
Seventh one has 40 + 4 = 44 poles
Eighth one has 44 + 4 = 48 poles
Now, we can get the total number of poles by adding the poles in all layers
<u>This is done as follows:</u>
Total number of poles = 20 + 24 + 28 + 32 + 36 + 40 + 44 + 48
Total number of poles = 272 poles
Hope this helps :)
