helleo i am new

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the probability of chosing the correct door is now 50%
where your previous option you had a probability of 0.33
you chances increase by 0.17 by switiching.
unless your a syrian goat herder without a drivers licence , you should switch.
do you think it matters in deal or no deal where there are only 2 remaining boxes?

I'm afraid you are wrong. By switching, your chance of a win goes up to 67%.

There is just one chance in three that you chose the right door to start with. Nothing changes that. By switching, BOTH the other scenarios turn into a win situation for you.

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Deal or no deal is rubbish. I watched it once, and was annoyed by the stupidity of the whole thing. Neither the contestants nor the hosts seem to have the slightest idea of what they are doing (just guessing, I think).

ok im sure i could be wrong.
but 0.67 sounds high.
i remember i read this somehwere and didnt follow the suppositions just the bottom line.
i thought it was 50% if you switch.
anyway are you a maths proff or a typical AS with too much time?

Does an MA from St. Johns, Cambridge count?

PS.... MathMikie.... sorry if donkey and I seem to be hijacking your welcome thread.

ahhh cambridge grad.
yeah sorry math mikie.

welcome to WP

nice to know you love math

what is the square root of -36

im not sure there is an answer to that.
any number squared is a positive number.

the answer is 6i mathematicians invented a number i to be the square root of -1 so the answer is 6i

hooo nice one.
i is the new number for the millenium, i phone, i pod, i number.
i see!

i am not that good at maths really i can't really do linear algebra very well solve the equations

p+q-r=0

2p-q+3r=3

-p-q=6

i have tried to solve them i know how to do it but i keep getting the wrong answer

i think your mssing some minus signs.
p=-5
r=6
q=11.

this works if 3 and 6 are minus.
perhaps the proff knows better?

Gosh... and I kept mixing up my signs, too, but...
p = 5, q = -11 and r = -6 will do fine.

p + q - r = (5) + (-11) - (-6) = 5 - 11 + 6 = 0
2p - q + 3r = 2(5) - (-11) + 3(-6) = 10 + 11 - 18 = 3
-p - q = -(5) - (-11) = -5 + 11 = 6

The easy bit is adding the first and last equations:
p + q - r = 0
-p - q = 6

p-p + q-q - r = 0 + 6
-r = 6
r = -6

Substitute back for r in the second to get
2p - q + 3(-6) = 3
2p - q - 18 = 3
2p - q = 21

We know
-p - q = 6

So subtract those...
3p = 21 - 6 = 15
p = 5

and finally
-p - q = 6
-5 - q = 6
q = -11

respect!