Question

Lots of points!! Help!!

Answer 1

Of the 12 available months, $r=4$ of them end in the letter "r" (Sep, Oct, Nov, Dec). The sample space consists of all 12 possible choices of 1 month, but the only outcome we care about is any 1 of these 4 being selected. The probability of choosing any one of these is $\dfrac4{12}=\dfrac13\approx0.33$. How you describe the probability is up to interpretation, but probably a good convention to use is to say that an event is "unlikely" to happen if that event has a probability less than 0.5 of occurring.