Question 330237
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The sum of a series of numbers is equal to the sum of the first number and the last number multiplied by the number of numbers and the product divided by 2.


For your problem, if they removed the first 17 rows of pipe, the first number in your series becomes 18.  The last is 24.


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \frac{(a\ +\ l)n}{2}\ =\ \frac{(18\ +\ 24)\ \cdot\ 7}{2}]


You can do your own arithmetic -- and you should be able to do it in your head.


John
*[tex \LARGE e^{i\pi} + 1 = 0]
My calculator said it, I believe it, that settles it
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