Question

Find the difference between the largest and the smallest number formed with the digits 1,3,9,and 5 without repetition.

Answer 1

To find the largest number formed by 1,3,9 and 5, arrange the digits in descending order.

9 > 5 > 3 > 1. So the largest number is 9531.

To find the smallest number formed by 1,3,9 and 5, arrange the digits in ascending order.

1 < 3 < 5 < 9. So the smallest number is 1359.

The difference between them is,

9531 - 1359 = 8172