In a simultaneous toss of $2$ coins,find the probability of getting $2$ tails.

From a class of $12$ girls and $18$ boys,two students are chosen randomly. What is the probability that both of them are girls?

$A$ bag contains $6$ red,$4$ white,and $8$ blue balls. If three balls are drawn at random,find the probability that $1$ is red and $2$ are white.

The chances of throwing a total of $3$ or $5$ or $11$ with two dice is

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.

$A$ locker can be opened by dialing a fixed three-digit code (between $000$ and $999$). $A$ stranger who does not know the code tries to open the locker by dialing three digits at random. The probability that the stranger succeeds at the $k^{th}$ trial is