In a certain lottery $10,000$ tickets are sold and $10$ equal prizes are awarded. What is the probability of not getting a prize if you buy one ticket?

Mr. $A$ has six children and at least one child is a girl. Then,the probability that Mr. $A$ has $3$ boys and $3$ girls is:

Let the sum of two positive integers be $24$. If the probability,that their product is not less than $\frac{3}{4}$ times their greatest positive product,is $\frac{m}{n}$,where $\operatorname{gcd}(m, n)=1$,then $n-m$ equals :

When two dice are rolled,what is the probability that at least one face shows a six?

An integer $x$ is chosen from $1$ to $50.$ Then the probability that $x + \frac{336}{x} \le 50$ is

If $P(A)=0.59, P(B)=0.30$ and $P(A \cap B)=0.21$,then $P(A^{\prime} \cap B^{\prime})$ is equal to