$4$ coins are tossed once. Find the probability of getting at least $1$ tail.

$2$ persons $A$ and $B$ throw a die alternately until $1$ of them gets a '$6$' and wins the game. Find the probability of $B$ winning.

$1$ 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.

Six boys and six girls sit in a row. What is the probability that the boys and girls sit alternatively?

Two numbers are selected at random from $1, 2, 3, \dots, 100$ and are multiplied. The probability, correct to two decimal places, that the product thus obtained is divisible by $3$ is:

Study the given information carefully to answer the question that follows. An urn contains $4$ green,$5$ blue,$2$ red,and $3$ yellow marbles. If $8$ marbles are drawn at random,what is the probability that there are equal numbers of marbles of each colour?