i Can't understand this problem

[dionys]

Hi guys i have a problem but i dont know how to start solving this
can you help?

We have three events:

A={The midday temperature in Hirakleio is 25C}
B={The midday temperature in Athens is 25C}
C={The maximum of the two midday temperatures in Hirakleio and Athens is 25[degrees]C}
P(A)=0.3
P(B)=0.4
P(C)=0.2

Find the probability that the minimum temperature between the two midday temperatures is 25C

[TenaliRaman]

Duh! seems like a pointless question unless they are defining C as AUB and D as AintersectionB where D is the required event.

In which case the simple Addition Principle does the job.

-- AI

[dionys]

so you say that :
P(D)=P(AintersectionB)=P(A)+P(B)-P(AUB)?

[HallsofIvy]

No, he DIDN'T say that! That would, in any situation at all, result in negative probabilities!