I get that too by my own method and a general formula too.

Bob

bobbym

2013-07-03 05:15:27

Agnishom

2013-07-03 03:42:11

Then?

bobbym

2013-07-03 03:37:10

You can not add them up.

Agnishom

2013-07-03 03:35:49

bob bundy wrote:

Agnishom wrote:

The Probability that the 1st Person chose dish X is 1/5. The Probability that the 2nd Person chose dish X is 1/5. The Probability that the 3rd Person chose dish X is 1/5. Therefore, the probability that anyone has chosen X before is 3/5.

That method is faulty. If there were 5 people before D, you would end up with 5/5 and no chance for D.

I'll work on an analytic method.

Bob

Ya, so... What to do?

Hi bobbym,

They ask me for a + b too

bobbym

2013-07-03 03:33:21

Must be different for me and you then. Mine requests a + b in a / b.

bob bundy

2013-07-03 03:32:26

Agnishom wrote:

The Probability that the 1st Person chose dish X is 1/5. The Probability that the 2nd Person chose dish X is 1/5. The Probability that the 3rd Person chose dish X is 1/5. Therefore, the probability that anyone has chosen X before is 3/5.

That method is faulty. If there were 5 people before D, you would end up with 5/5 and no chance for D.

I'll work on an analytic method.

Bob

Agnishom

2013-07-03 03:29:33

I would say yes, because the answer you gave me works

bobbym

2013-07-03 03:22:01

Is that the exact question?

Agnishom

2013-07-03 03:20:55

Consider that the 4th person chose dish X.

The Probability that the 1st Person chose dish X is 1/5. The Probability that the 2nd Person chose dish X is 1/5. The Probability that the 3rd Person chose dish X is 1/5. Therefore, the probability that anyone has chosen X before is 3/5.

So, the possibility that the dish is previously not chosen is 2/5

bobbym

2013-07-03 03:16:58

Although I have the exact answer by experimental methods I am still working on a good solid method that would please an olympic dude.

Agnishom

2013-07-03 03:10:27

New Problem There are 5 kinds of dishes i, ii, iii, iv, and v. Four Customers A, B, C and D choose a dish at random. What is the probability that person D chooses a previously unordered dish?

bobbym

2013-07-03 02:59:37

Yes, if you are signed in as a member.

Agnishom

2013-07-03 02:47:14

The Featured Solution: https://brilliant.org/i/b6ozMJ/