From the word $POSSESSIVE$, a letter is chosen at random. The probability of it being $S$ is:

The corners of regular tetrahedrons are numbered $1, 2, 3, 4$. Three tetrahedrons are tossed. The probability that the sum of the upward corners will be $5$ is

$A$ bag contains $4$ white,$5$ black,and $6$ red balls. If a ball is drawn at random,what is the probability that the drawn ball is either white or red?

If in a lottery there are $5$ prizes and $20$ blanks,then the probability of getting a prize is

$A$ and $B$ toss a coin alternatively,the first to show a head being the winner. If $A$ starts the game,the chance of his winning is

$1$ bag contains $4$ white and $2$ black balls. Another bag contains $3$ white and $5$ black balls. If $1$ ball is drawn from each bag,find the probability that $1$ ball is white and $1$ ball is black.