How do I solve this?

[Neo]

Originally Posted by Canyarion

Pf, that should be very easy.

First I thought of 30/365, then of 29/365, but none of those were 0.71.

Ok, let's compare it with throwing dice. Let's say you throw a dice 2 times. How big is the chance that at least 2 throws are the same? 1/6. Throw it 3 times: (1/6 +1/6) eeeeeeuh crap, it's 0:30 here, I'm tired and I just had a glass of wine. I don't think it matters what the other rolls(/dates) are once you have 1 the same. So no taurenpoopie of double chances or so to speak.

But that would still bring me to 29/365 = 0.079.

Blast, I should know this.

Edit: I only looked at the chance of the same as the first. It's also the chances of others being the same. So it's 29/365 + 28/365 + 27/365..... = ???

Edit3: I probably made another mistake, because that gives a probability of 1.09 something.

Don't feel bad, it took mathematicians a long time to figure out how to calculate those kinds of probabilities.