Dr Pooranmal and Ashfaq A Khan Solutions for Chapter: Factors and Multiples, Exercise 1: EXERCISE 4.1

Check if the following number is a multiples of $21$ or not.

$21630$

Without actually dividing, show that $11$ is a factor of the following number:

$1111$

Without actually dividing, show that $11$ is a factor of the following number:

$11011$

Without actually dividing, show that $11$ is a factor of the following number:

$110011$

Without actually dividing, show that $11$ is a factor of the following number:

$1100011$

Is there any natural number having no factor?

Write the numbers having exactly one factor.

Find the numbers between $1$ and $50$ having exactly three factors.