$A$ ball is drawn at random from a box containing $6$ red balls,$4$ white balls and $5$ blue balls. What is the probability that it is red?

Six boys and six girls sit in a row. What is the probability that the boys and girls sit alternatively?

The probabilities of a student getting $I, II$ and $III$ division in an examination are respectively $\frac{1}{10}, \frac{3}{5}$ and $\frac{1}{4}$. The probability that the student fails in the examination is

In a college,$25\%$ of the boys and $10\%$ of the girls offer Mathematics. The girls constitute $60\%$ of the total number of students. If a student is selected at random and is found to be studying Mathematics,the probability that the student is a girl,is

$2$ dice are thrown. Find the probability of getting a sum more than $7$.

The probability of an event $A$ occurring is $0.5$ and that of $B$ is $0.3$. If $A$ and $B$ are mutually exclusive events,find the probability that neither $A$ nor $B$ occurs.