# Help understanding the solution to this fraction problem.

1. Dec 8, 2008

### limac

Hi,

Please see the attachment.

I really don't understand what the M/7 and the L/13 represents. How did he(authors) logically derive to that? And also, I don't understand how finding the value in-between M/7 and L/13 (M+L/20) helps them come up with the solution and the proof.

Thank you,
limac

2. Dec 8, 2008

### adriank

Where is the attachment?

3. Dec 9, 2008

### limac

Here, How about this?

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123
4. Dec 9, 2008

### adriank

Given an integer k from 1 to 6, and an integer l from 1 to 12, k/7 and l/13 are positions of a red mark and a green mark, respectively (where the stick goes from 0 to 1). The idea is that in between any red mark and any green mark, there is a point at (k + l)/20 where the stick is cut (since the stick is cut at 1/20 intervals).

5. Dec 9, 2008

### limac

adriank,

Alright, so k and l are representing any one valid mark at a time on the stick. And (k+l)/20 is the point in-between any two of the respective red and green marks, right?

Now, it is making sense to me. I was very confused about what k/7 and l/13 meant.

Thank you very much for your time. :)

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