$5$ boys and $5$ girls are sitting in a row randomly. The probability that boys and girls sit alternatively is

When two dice are rolled,what is the probability that the sum of the numbers appearing is a multiple of $3$?

$A$ bag contains $30$ balls,of which $10$ are red,$5$ are blue,and $15$ are white. Find the probability of drawing a coloured ball at random.

The chance of throwing at least $9$ in a single throw with two dice is:

$A$ man speaks truth in $80 \%$ of the cases and another in $90 \%$ of the cases. While stating the same fact,what is the probability that they contradict each other?

The probability that $A$ speaks the truth is $\frac{4}{5}$,while this probability for $B$ is $\frac{3}{4}$. Find the probability that they contradict each other when asked to speak on a fact.