Need and equation

[Kirk30096]

I'm a curious electrician. Say I have 600" run of wire that I have to pull through studs in 32" increments. That is to say, the first pull is 600", the second pull is 568", the third is 536" and so on until I reach the end of the run. How do I express the total of inches of pull?

Thanks.

 

[MarkFL]

Hello, and welcome to FMH!

You'll be able to make 18 pulls, with 24" left over, so the sum may be written as:

[MATH]S=\sum_{k=0}^{18}(32k+24)=8\sum_{k=0}^{18}(4k+3)=8(2(18\cdot19)+3(19))=5928[/MATH]

 

[Kirk30096]

Thanks.