Hi Farina,
P(neither A or B) = 1  P(A or B) since, for the event "neither A nor B" to occur, Both A and B cannot occur. You can 1  P(A or ) since
P(A or B) = P(A) + P(B)  P(A and B)
For part F), you know that there are 31 days in June and you know P(B). Here you might think of P(B) as the proportion of the time that the temperature is over 25 deg C. Thus you would expect that this is the proportion of the days in June when the temperature is over 25 degrees C. Hence the expected number of days in June when the temperature is over 25 deg C is
P(B) 31
Penny
