## Problem 569

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mctrafik
Posts: 27
Joined: Thu Oct 06, 2011 5:42 am
Location: Los Angeles, California
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### Problem 569

I worked this out by hand, but I can't seem to verify
"from the 9th mountain, he can see three peaks, those of the 5th, 7th and 8th mountain"

If, the mountain peaks were on a grid, then their coordinates would be :
9 - (430, 30)
8 - (328, 26)
7 - (238, 22)
5 - (100, 16)

The slope from 9th peak to 5th peak is (30 - 16) / (430 - 100) = 0.04242424242
But 9th to 8th peak is (30 - 26) / (430 - 328) = 0.03921568627

This means that 8th peak is blocking the view for 5th.

"Nothing in this world that's worth having comes easy"

mpiotte
Posts: 1914
Joined: Tue May 08, 2012 4:40 pm

### Re: Problem 569

mctrafik wrote:...
If, the mountain peaks were on a grid, then their coordinates would be :
9 - (430, 30)
...
I would double check this value if I were you.

mctrafik
Posts: 27
Joined: Thu Oct 06, 2011 5:42 am
Location: Los Angeles, California
Contact:

### Re: Problem 569

Ah yes. That one's off. Thank you. Funny thing is when making primes by hand... "49" isn't prime.

"Nothing in this world that's worth having comes easy"