.
The number of pipes is this sum
1 + 2 + 3 + 4 + . . . + 96. (*)
It is the sum of the first 96 natural numbers (arithmetic progression).
It is well known fact that the sum of the first "n" natural numbers is equal to .
So, in your case the sum of the numbers (*) is equal to = 4656.
The last step in solution of this problem is to multiply the found number of pipes 4656 by 8 and by 0.12
to get the answer in dollars.
I leave it to you to complete this simple calculation.
Have fun (!)
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For introductory lessons on arithmetic progressions see
- Arithmetic progressions
- The proofs of the formulas for arithmetic progressions
- Problems on arithmetic progressions
- Word problems on arithmetic progressions
in this site.
Also, you have this free of charge online textbook in ALGEBRA-II in this site
- ALGEBRA-II - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Arithmetic progressions".
Save the link to this textbook together with its description
Free of charge online textbook in ALGEBRA-II
https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson
into your archive and use when it is needed.