@Dave,
Yeah, I had read those numbers on internet as this puzzle is well known.
However I am not convinced with the calculations because of following 2
points:

1) If C shoots in air, the probability of survival is more for the
probabilities considered in the calculations with which A & B will shoot at
him.
Now, if A & B are intelligent, they will know that increasing survival
probability for C is bad for them (you can calculate survival probability
for A & B in each case), and therefore they will shoot at C with higher
probability than what they were planning earlier.

2) C's survival probability depends on P(A shooting at C) * 1 and P(B
shooting at C) * 1/2.
If C shoots at A, P(A shooting at C) is less by 33% and P(B shooting at C)
is more by 33%. So, if P(A shooting at C) dominates by logic in 1st point,
C's survival probability will be now more.



On Sun, Jan 2, 2011 at 7:59 AM, Dave <dave_and_da...@juno.com> wrote:

> @Salil: Working out the probabilities, we find that:
>
> 1. If C initially shoots at A, C's probability of survival is ~
> 0.35867.
> 2. If C initially shoots at B, C's probability of survival is ~
> 0.27679.
> 3. If C initially shoots in the air, C's probability of survival is ~
> 0.49624.
>
> Dave
>
> On Jan 1, 11:30 am, Salil Joshi <joshi.sali...@gmail.com> wrote:
> > @Rahul,
> > As per my understanding,
> > In any round P(C is dead) = P(A is alive * A shoots C * A's shot is
> > accurate) + P(B is alive * B shoots C * B's shot is accurate)
> > this is to be minimized.
> > by not shooting at either A or B in 1st chance, how is this probability
> less
> > for C?
> >
> > On Sat, Jan 1, 2011 at 10:43 PM, Salil Joshi <joshi.sali...@gmail.com
> >wrote:
> >
> >
> >
> >
> >
> > > @Rahul,
> > > What purpose is served by wasting the shot? If C shoots at A or B, at
> least
> > > some probability that C is dead in future will be reduced.
> >
> > > On Sat, Jan 1, 2011 at 10:14 PM, RAHUL KUJUR <
> kujurismonu2...@gmail.com>wrote:
> >
> > >> @snehal:
> > >> will the shooting take place in increasing order of accuracy of
> hitting
> > >> the target and is that at a time only one person can take a shot???
> > >> if yes then
> > >> @Salil:
> > >> my answer would be the same as above. what C will do is that it will
> first
> > >> let A and B kill each other first.
> > >> After C wastes his shot it will be B's turn. B can kill C, but in that
> > >> case the turn would go to A and he would surely kill B. If B goes
> after A,
> > >> then B may hit it or miss it(as its probability of hitting is 50%)
> > >> If B misses it
> > >> then
> > >> it depends on A whom to kill. A may kill B or C. A will try to kill
> one
> > >> who is better shooter i.e. B as C is less likely to hit A.
> > >> If B hits A then we are done. Round 1 is complete(as required in the
> > >> question) and C survives the first round.
> > >> Look the problem is not that who gets killed at last but rather what C
> > >> should fire in the first round obviously to survive(as I understood
> the
> > >> problem). It may happen that eventually C gets killed. But what should
> C
> > >> shoot in first round to survive.
> >
> > >> --
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> > > --
> >
> > > --------
> > > Thanks & Regards
> > > Salil Joshi.
> > > CSE MTech II, IITB
> > > A-414, Hostel 12
> > > +91.9819.442.865
> >
> > > This is a confidential E-Mail. If it has reached you by mistake or if
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> >
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> > Thanks & Regards
> > Salil Joshi.
> > CSE MTech II, IITB
> > A-414, Hostel 12
> > +91.9819.442.865
> >
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-- 

--------
Thanks & Regards
Salil Joshi.
CSE MTech II, IITB
A-414, Hostel 12
+91.9819.442.865


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