$A$ bag contains $3$ white and $5$ black balls. If one ball is drawn,then the probability that it is black,is

Two dice are thrown simultaneously. What is the probability of obtaining a sum of the numbers less than $11$?

Let $S$ be the sample space of all five-digit numbers. If $p$ is the probability that a randomly selected number from $S$ is a multiple of $7$ but not divisible by $5$,then $9p$ is equal to.

Let $S$ be a set containing $n$ elements. If we select $2$ subsets $A$ and $B$ of $S$ at random,then the probability that $A \cup B = S$ and $A \cap B = \phi$ is:

Two dice are rolled simultaneously. The probability that the sum of the two numbers on the dice is a prime number is:

The probability of obtaining an even prime number on each die,when a pair of dice is rolled,is . . . . . . .