<t>QuoteOriginally posted by: dropoutmathguy, do you mind posting a little more detail?the idea is to compute the expectation by conditioning and obtaining an equation for E[N]: E[N] = E[E[N|R1]] = P(R1=1/3/4/5/6)*(E[N]+1)+P(R1=2)*( P(R2=3)*2 + P(R2 = 1/4/5/6)*(E[N]+2) + P(R2 = 2)*(repeating the sam...

<t>QuoteOriginally posted by: warherothat dice question is lame... here is a slightly less lame variant:what is the number of expected rolls of a dice to consecutively get a 2-3 ???through conditioning and some infinite series unpleasentness, i get 11. something like:m = 5/6(m+1)+sum(j/6^j)+4*sum((m...

<t>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, identif...

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.

<t>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 yo...

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

<t>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 ...

<t>QuoteOriginally posted by: QwertyYuiopFor the question about the sun's rays, you need to realize the two observers do not agree on what time dawn actually takes place. You must determine the difference in the time of dawn between the person on the ground and the person on top of the monument. Sin...

<t>QuoteOriginally posted by: krok, let's ask again... I want to solve the staircase puzzler but there seems to be a problem:1) I assume the arrangement isA_B_C__D_E_F____G_H_I2) If all rowsums are the same, then 3R = 1+2+3+4+5+6+7+8+9=4.10+5 = 45 and R = 153) Obviously A != 15 and I != 15, so the t...

<t>QuoteOriginally posted by: krok, much easier to do recursively with bunnyjumps, I agree J(n) = J(n-2)+J(n-1) for n>3, J(1)=1, J(2)=2. db query thing is pretty easy, just select from two copies of the same table by renaming i.e.SELECT X.Value, Y.Value FROM Table AS X, Table As Y; gay abe's monumen...

<t>QuoteOriginally posted by: mathguyI interviewed with their stat arb team in NY and really liked the problems they asked me to solve. They seemed like nice folks too.i've been asked a few times the questions i was asked, so to save me some typing, here are a few that i can remember:-if i'm standin...

I interviewed with their stat arb team in NY and really liked the problems they asked me to solve. They seemed like nice folks too.

i interviewed there (2 times) and were quite impressed. one of the guys i met was an IMO medalist and quite an intelligent (and nice) guy. the rest were also very cool (both smart and personally).

<t>QuoteOriginally posted by: SabeenaQuoteOriginally posted by: mathguyJust found a job--took me 9 months. Don't give up!Could you please share with us how many interviews did you go to? how many final stage? how long did the whole interviewprocess took?In my experience things are moving pretty slow...

In my opinion, programming should be fairly easy to a good Mathematician. I don't know if I am a good mathguy (despite the nick), but always found coding much easier than math.