Telephone poles are stored in a pile with 30 poles in the first layer, 29 in the second, and so on. If there are 12 layers, how many telephone poles does the pile contain?

294

Step-by-step explanation:

Given

First layer has 30 Poles

Second layer has 29 Poles

There are twelve layers

It follows an A.P. with first term and common difference

Sum of n terms of an A.P. is

Insert the values

So, there are 294 Poles in 12 layers

560

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