s*****a
发帖数: 19 | 1 If you roll 5 standard six-sided dice, what's the probability that you get a
t least two 4s?
Also: you were offered the following bet: we pay you $1000 if you roll at le
ast two 4s but you have to pay Rapleaf $1000 if you don't. Would you take
the bet? Why or why not? |
d*j
发帖数: 13780 | 2 from SIG ?
a
le
take
【在 s*****a 的大作中提到】
: If you roll 5 standard six-sided dice, what's the probability that you get a
: t least two 4s?
: Also: you were offered the following bet: we pay you $1000 if you roll at le
: ast two 4s but you have to pay Rapleaf $1000 if you don't. Would you take
: the bet? Why or why not?
|
p*****k
发帖数: 318 | 3 hmm... why rapleaf then?
1-[(5/6)^5+5*(1/6)*(5/6)^4] ~ 0.2 |
s*****a
发帖数: 19 | 4 yes, i agree with this answer.
how do we decide whether to bet? do we NOT bet simply because 0.2 < 0.5?
【在 p*****k 的大作中提到】
: hmm... why rapleaf then?
: 1-[(5/6)^5+5*(1/6)*(5/6)^4] ~ 0.2
|
a**m
发帖数: 102 | 5 who is Rapleaf？
a
le
take
【在 s*****a 的大作中提到】
: If you roll 5 standard six-sided dice, what's the probability that you get a
: t least two 4s?
: Also: you were offered the following bet: we pay you $1000 if you roll at le
: ast two 4s but you have to pay Rapleaf $1000 if you don't. Would you take
: the bet? Why or why not?
|
n********n
发帖数: 221 | |
i*****r
发帖数: 1302 | |
f*******r
发帖数: 198 | 8 this solution sounds reasonable to me. could you help me figure out what's
wrong with this solution:
C(4,5) * (1/6)^2 = 10/36
【在 p*****k 的大作中提到】
: hmm... why rapleaf then?
: 1-[(5/6)^5+5*(1/6)*(5/6)^4] ~ 0.2
|
s*****t
发帖数: 737 | 9 does his solution sound reasonable to you? His solution is right.
I bet you dont understand it from your solution.
【在 f*******r 的大作中提到】
: this solution sounds reasonable to me. could you help me figure out what's
: wrong with this solution:
: C(4,5) * (1/6)^2 = 10/36
|
o*****n
发帖数: 2098 | 10 You mean C(2,5)*(1/6)^2?
In your method, you count several times for some cases. For example, if
there are three 4s, your method will count 3 times for this case.
4 4 4 X X
^ ^ _ C(2,5)
4 4 4 X X
^ _ ^ C(2,5)
4 4 4 X X
_ ^ ^ C(2,5)
It is difficult to calculate the probability directly.
【在 f*******r 的大作中提到】
: this solution sounds reasonable to me. could you help me figure out what's
: wrong with this solution:
: C(4,5) * (1/6)^2 = 10/36
|
f*******r
发帖数: 198 | 11 ah i see. thank you so much!
果然还是quant版牛人多啊。。。
【在 o*****n 的大作中提到】
: You mean C(2,5)*(1/6)^2?
: In your method, you count several times for some cases. For example, if
: there are three 4s, your method will count 3 times for this case.
: 4 4 4 X X
: ^ ^ _ C(2,5)
: 4 4 4 X X
: ^ _ ^ C(2,5)
: 4 4 4 X X
: _ ^ ^ C(2,5)
: It is difficult to calculate the probability directly.
|
f*******r
发帖数: 198 | 12 yeah i got his answer, and i did post it wrong. what i mean is C(2,5), not C
(4,5), though they are the same.
BTW, the next replay gives me the answer, thank you anyway.
【在 s*****t 的大作中提到】
: does his solution sound reasonable to you? His solution is right.
: I bet you dont understand it from your solution.
|
