QuoteOriginally posted by: QwertyYuiopQuoteOriginally posted by: mathguyi just did it again and am getting something like 24 secs. i could be wrong, but .024 secs is maybe too fast.i am assuming the Earth's R is about 6378000 meters (from Google).No way. That would mean from, say, the 45th floor of an office building, you'd get sunrise over five minutes early. I think you may have missed something in your calculation.for 45 floors, assuming 3 meters per floor, i get 89.47 seconds, which is plausible for me. i fail to understand how you translated 24 seconds for 10 meters high monument to 5 minutes for a ~135 meters high building. maybe you need to reconsider your logic. or the lack of it.

QuoteOriginally posted by: kr9_2_3____4____7_6_1________8________5woohooooany proof you did something analytical and not used a cpu?

ok, how 'bout an indirect proof?52B43__6__981____A____7 72D45__6__B83____A____9C1

QuoteOriginally posted by: mathguyfor 45 floors, assuming 3 meters per floor, i get 89.47 seconds, which is plausible for me. i fail to understand how you translated 24 seconds for 10 meters high monument to 5 minutes for a ~135 meters high building. maybe you need to reconsider your logic. or the lack of it.I think you should check your math. Your numbers are wrong. Your time difference of 24 seconds for a 10 meter building leads to the following:24 seconds/10 meters == 2.4 seconds per meter.2.4 s/m * 135 m == 324 seconds324 seconds / 60 seconds per minute == 5.4 minutesThe correct answer for the original question should be the 0.024 seconds I originally outlined. That leads to a more reasonable time difference of 0.3 seconds for a 135m building.If you still disagree with me, by all means prove me wrong.

QuoteOriginally posted by: QwertyYuiopQuoteOriginally posted by: mathguyfor 45 floors, assuming 3 meters per floor, i get 89.47 seconds, which is plausible for me. i fail to understand how you translated 24 seconds for 10 meters high monument to 5 minutes for a ~135 meters high building. maybe you need to reconsider your logic. or the lack of it.I think you should check your math. Your numbers are wrong. Your time difference of 24 seconds for a 10 meter building leads to the following:24 seconds/10 meters == 2.4 seconds per meter.2.4 s/m * 135 m == 324 seconds324 seconds / 60 seconds per minute == 5.4 minutesThe correct answer for the original question should be the 0.024 seconds I originally outlined. That leads to a more reasonable time difference of 0.3 seconds for a 135m building.If you still disagree with me, by all means prove me wrong.what you are saying is that time_diff(monument_hight) = A*monument_hight; what I am saying is that time_diff(m_h) = acos(R/(R+m_h))*24*60*60/(2*PI). not linear. by all means you are wrong.

QuoteOriginally posted by: krok, how 'bout an indirect proof?52B43__6__981____A____7 72D45__6__B83____A____9C1that's curious. i wonder how you noticed it.

mathguy you are such an ass - that's why you have the shit-eating-grin icon i guessbut to answer your question, I answered it the same way any mathematician provides a proof by induction: solved the easy cases by hand where the number of permutations is small, identified the pattern, and extrapolatedcurious that you are mathguy and didn't know this

QuoteOriginally posted by: krmathguy you are such an ass - that's why you have the shit-eating-grin icon i guessbut to answer your question, I answered it the same way any mathematician provides a proof by induction: solved the easy cases by hand where the number of permutations is small, identified the pattern, and extrapolatedcurious that you are mathguy and didn't know thisdidn't mean to offend you. i actually thought it was quite neat you noticed this pattern. i was simply wondering how you acheived it.

guys i am a new member and was kinda browsing through the forums....came accross this bunny problem. i think it is quite simple actually. Question: possible solutions of x and y from x+2y=nAnswer: ceil(n+1/2) i.e.if n is even, possible combinations are (n/2)+1if n is odd, possible combinations are (n+1)/2proof: 1.if n is even, x needs to be even also. possible solutions for x is (0,2,4...n/2) i.e a total of (n/2)+1 values. corresponding values for y can be trivially found2. if n is odd, x needs to be odd as well. possible solutions for x is (1,3...n) i.e. a total of (n+1)/2 values. check:let n=8. x can be (0,2,4,6,8)let n=9 x can be (1,3,5,7,9)

you have to include the jump permutations too - i.e. 2,1,1 is different from 1,2,1 is different from 1,1,2if you do that, you arrive at my first solutionunfortunately, you'd have to be a combinatorics genius to see that that formula obeys the Fibanocci relation... it's easier to just spell out the recurrence relation and finish the problem directly