Three balanced coins are tossed simultaneously. Find the probability of receiving at least two heads.

$12$ defective pens are accidentally mixed with $132$ good ones. It is not possible to just look at a pen and tell whether or not it is defective. One pen is taken out at random from this lot. Determine the probability that the pen taken out is a good one.

In any situation that has only two possible outcomes,each outcome will have a probability of $\frac{1}{2}$. True or false? Why?

$A$ card is drawn at random from a well-shuffled pack of $52$ cards. The probability of that card being a card of a black suit is .............

$A$ card is selected at random from a well-shuffled pack of $52$ cards. Find the probability that the selected card is that of spades.

In a musical chair game,the person playing the music has been advised to stop playing the music at any time within $2 \, \text{minutes}$ after she starts playing. What is the probability that the music will stop within the first half-minute after starting?