If from each of the three boxes containing $3$ white and $1$ black,$2$ white and $2$ black,and $1$ white and $3$ black balls,one ball is drawn at random,then the probability that $2$ white and $1$ black ball will be drawn is

Let $A = \{1, 3, 5, 7, 9\}$ and $B = \{2, 4, 6, 8\}$. If an ordered pair $(a, b)$ is chosen at random from the Cartesian product $A \times B$,what is the probability that $a + b = 9$?

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

Two students Anil and Ashima appeared in an examination. The probability that Anil will qualify the examination is $0.05$ and that Ashima will qualify the examination is $0.10$. The probability that both will qualify the examination is $0.02$. Find the probability that both Anil and Ashima will not qualify the examination.

Statement-$I$: If a leap year is selected at random,the probability of it having $53$ Sundays is $2/7$.
Statement-$II$: $A$ leap year has $366$ days.

$A$ box contains $4$ white pens and $2$ black pens. Another box contains $3$ white pens and $5$ black pens. If one pen is selected from each box,then the probability that both the pens are white is equal to