$3$ coins are tossed. Find the probability of getting all heads.

The probability of India winning a test match against West Indies is $\frac{1}{2}$. Assuming independence from match to match,the probability that in a $5$ match series India's second win occurs at the third test,is

$A$ bag contains $5$ white,$7$ red,and $8$ black balls. If four balls are drawn one by one without replacement,what is the probability that all are white?

$A$ ticket is drawn from $200$ tickets numbered from $1$ to $200.$ Find the probability that the number is divisible by $2,$ $3,$ or $5.$

The probability of hitting a target by three marksmen are $\frac{1}{2}, \frac{1}{3}$ and $\frac{1}{4}$ respectively. The probability that one and only one of them will hit the target when they fire simultaneously,is

The probability of getting heads in all the three trials,when a balanced coin is tossed thrice,is