Question

Form the largest and the smallest $4$-digit numbers using each of the digits $9,3,0,7$.

Answer 1

Step 1: Forming smallest number:

While forming smallest number, arrange the digits in ascending order.

Here, $0<3<7<9$.

But $0$ at thousands place would result in $3$-digit number. So, rearranging $0,3$.

So, the smallest $4$-digit number is $3079$.

Step 2: Forming largest number:

While forming largest number, arrange the number in descending order.

Here, $9>7>3>0$.

So, the largest $4$-digit number is $9730$.

Thus, the largest and the smallest $4$-digit numbers using each of the digits $9,3,0,7$ are $9730$ and $3079$ respectively.