A doctor in Michigan has a sister who lives in California but the sister does not have any brother that lives in Michigan, how come??
:P

Divdude,
Your reasoning is right but your calculation is wrong.The half of 9.8 is 4.9 not 4.4.
Slacdemic,
Though there is no direct relation between physics and the color of bear, you need some knowledge of physics to solve this problem.
It is only possible that a bear to fall 5 meter in 1 second if value of g( accleration due to gravity) is 10m/s^2. The value of g is larger at the poles. The larger value of g at the poles is not due only to differences in the radii of the earth, but that other factors are also responsible such as the rotation of the earth and the increase in the earth's density toward its center. For the incident to be true, it can not be other places on earth but poles where polar bear (white bear) are found.

@gemmi
I am not sure about the right answer but I can tell you one of the fastest way
to do it. It works like a search tree.

Lets consider t be the time from when the mouse starts to show abnormal effects.
First lets divide the bottles into 10 groups 100 each. Then mix the water from
all the bottle of each group and make one water solution for each group. Now we make
each mouse drink water from one of the solution and we note this down. After time t
the mouse will start to show the effects of poison and we can identify which group the
poisoned water is in. We discard the poisoned mouse and continue dividing again.
Let me simulate the whole process.

t=0
no of mice=10
bottles/group=100

t=1
no of mice=9
bottles/group=11 for 8 groups and 12 for a group

t=2
no of mice=8
bottles/group=
if group containing 11 bottles had poison:1 each for 5 groups and 2 each for 3 groups
if group containing 12 bottles had poison:1 each for 4 groups and 2 each for 4 groups

By now the chance of finding poisoned bottle is more than 50 % but there are groups
with 2 bottles.
t=3
no of mice=7
bottles/group=1

So the mininimum time require will be equal to 3t and maximum time will be equal to 4t


This is just a method, the correct answer might suggest better method.
for this method to work value of t should be 2.5 hrs.

divdude, your algo is ok but it will take at least 3t hours, and, as i said earlier, t=10hrs in the question. Also, the total time available is T=10 hrs only. Rats are to be made drink water samples at the beginning of the 10 hr period and observations are to be made at the end of the period. No intermediate observations or conslusions are envisioned.

[Hint: Think Digital]

@gemmi Let me have another go.
For simplicity consider there are only 8 bottles and 3 testers
let 1 represent bottle tasted by the mouse and 0 represent bottle not tasted by mouse

Bot1 bot2 bot3 bot4 bot5 bot6 bot7 bot8
ms1 1 0 1 0 1 0 1 0
ms2 1 1 0 0 1 1 0 0
ms3 1 1 1 1 0 0 0 0

so if mouse 1 died bottle2 is poisonous which is obvious from chart.
similar conclusions can be reached if mouse 2 and 3 died.
Similar method could be extended for 1000 bottles of watertoo.
Hope this is okay.

Simple arithmetic question from myself.
You have 100lb of potatoes, which consists of 99% water. If, after being left in the sun, some water has evaporated, so that the potatoes are only 98% water, what is the mass of the potatoes now?

@gemmi well i think if i happen to think digital

1000 = 1
10= 1

Guest4, you never explained the logic behind the answer, man!

divdude, you've got the answer!! According to ur chart, if all the rats die, it can be concluded that bottle 1 conatains poison; if rats 1 and 3 die, bottle 3 contains poison; if only rat 1 dies, bottle 7 contains poison, and so on.

The basic idea here is that with n rats we can have a unique combination of rat(s) tasting water from each of 2^n bottles. So, the combination of rats that die will indicate which bottle contains poisonous water.

freek, i don't see how both of them are 1.

divdude, wt. of potatoes remaining = 50 lb.

Try this,

http://www.thaigoodview.com/library/game/logic3falls.html