A man and his wife appear for an interview for two posts. The probability of the husband's selection is $\frac{1}{7}$ and that of the wife's selection is $\frac{1}{5}$. What is the probability that only one of them will be selected
$\frac{1}{7}$
$\frac{2}{7}$
$\frac{3}{7}$
None of these
A bag contains $9$ discs of which $4$ are red, $3$ are blue and $2$ are yellow. The discs are similar in shape and size. A disc is drawn at random from the bag. Calculate the probability that it will be red.
Two dice are thrown. The events $A, B$ and $C$ are as follows:
$A:$ getting an even number on the first die.
$B:$ getting an odd number on the first die.
$C:$ getting the sum of the numbers on the dice $\leq 5$
Describe the events $B$ or $C$
A card is drawn from a well shuffled pack of cards. The probability of getting a queen of club or king of heart is
Three identical dice are rolled. The probability that same number will appear on each of them will be
In each of the following experiments specify appropriate sample space A boy has a $1$ rupee coin, a $2$ rupee coin and a $5$ rupee coin in his pocket. He takes out two coins out of his pocket, one after the other.