R K Bansal Solutions for Chapter: Set Concepts, Exercise 1: EXERCISE 13(A)

Find whether the following collection represents a set or not:

The collection of good students in your school.

Find whether the following collection represents a set or not:

The collection of the numbers between $30$ and $45$.

Set $\{4, 5, 8\}$ is the same as the set $\{5, 4, 8\}$ and the set $\{8, 4, 5\}$.
 

Sets $\{\mathrm{a}, \mathrm{b}, \mathrm{m}, \mathrm{n}\}$ and $\{\mathrm{a}, \mathrm{a}, \mathrm{m}, \mathrm{b}, \mathrm{n}, \mathrm{n}\}$ are same.
 

Set of letters in the word $\text{'}suchismita\text{'}$ is $\{s\mathit{,}\mathit{ }u\mathit{,}\mathit{ }c\mathit{,}\mathit{ }h\mathit{,}\mathit{ }i\mathit{,}\mathit{ }m\mathit{,}\mathit{ }t\mathit{,}\mathit{ }a\}$.
 

Set of letters in the word $\mathit{\text{'}}MAHMOOD\mathit{\text{'}}\mathit{ }$ is $\{M\mathit{,}\mathit{ }A\mathit{,}\mathit{ }H\mathit{,}\mathit{ }O\mathit{,}\mathit{ }D\}$.

Express the following set in set-builder notation (form):
$\left\{\frac{1}{3}, \frac{1}{4}, \frac{1}{5}, \frac{1}{6}, \frac{1}{7}, \frac{1}{8}\right\}$
 

Given: $\mathrm{A}=\{\mathrm{x}:\mathrm{x}$ is a multiple of $2$ and is less than $25\}$
$\mathrm{B}=\{\mathrm{x}:\mathrm{x}$ is a square of a natural number and is less than $25 \}$
$\mathrm{C}=\{\mathrm{x}:\mathrm{x}$ is a multiple of $3$ and is less than $25 \}$
$\mathrm{D}=\{\mathrm{x}:\mathrm{x}$ is a prime number less than $25\}$
Write the sets $\mathrm{A}, \mathrm{B}, \mathrm{C}$ and $\mathrm{D}$ in roster form.