$A$ die is formed so that the probability of getting a number $i$ when it is rolled is proportional to $i$ $(i=1, 2, 3, 4, 5, 6)$. The probability of getting an odd number on the die when it is rolled is

If there are $4$ red,$3$ pink,$5$ yellow,and $8$ white roses in a garden,what is the probability that a blind person touches a red or a white rose?

What is the probability of having $53$ Sundays in a non-leap year?

In a college, $40 \%$ of students attend the Mathematics class, $30 \%$ of students attend the Physics class, and $20 \%$ of students attend both classes. If a student is chosen at random from the college, what is the probability that the chosen student attends only one class?

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

Two brothers $X$ and $Y$ appeared for an exam. Let $A$ be the event that $X$ has passed the exam and $B$ is the event that $Y$ has passed. The probability of $A$ is $\frac{1}{7}$ and of $B$ is $\frac{2}{9}$. Then,the probability that both of them pass the exam is