Question

Make the greatest and the smallest four digit numbers using any four different digits with condition as given :

Digit $1$ is always at thousands place.

Answer 1

Step 1 : To make the greatest four digit numbers using any four different digits with given condition :1

We know that there are ten digits in mathematics, that is, $0,1,2,3,4,5,6,7,8,9$

In order to write the greatest four digit number by using the digits $9,8,6$and $1$ is always at thousands place, arrange the digits in descending order.

Thousands	Hundreds	Tens	Ones
$1$	$9$	$8$	$7$

The greatest four digit $=1987$

Step 2 : To make the smallest four digit numbers using any four different digits with given condition :

In order to write the smallest four digit number by using the digits $0,2,3$and $1$ is always at thousands place, arrange the digits in ascending order. Also, keep $0$ at hundreds place.

Thousands	Hundreds	Tens	Ones
$1$	$0$	$2$	$3$

The smallest four digit $=1902$

Hence, the greatest and the smallest four digit numbers using any four different digits with condition $1$ is always at thousands place are $1987$ and $1023$ respectively.