Form the greatest and smallest `4` digit numbers with digits `9,3,7` and `1` .

Form the greatest and the smallest four-digit number using the digits 9, 3, 8, and 1 without repetition, such that 1 is at the third place of the number.

Form the largest and smallest 4-digit numbers using each of digits 7, 1, 0, 5 only once.

What is the smallest 3-digit number with unique digits?

Write the greatest and the smallest 5-digit numbers, using the digits (digits may repeat): 1, 3 and 7

Write the greatest and the smallest 5-digit numbers, using the digits (digits may repeat): 3, 0, 5 and 7

Write the greatest and the smallest 5-digit numbers, using the digits (digits may repeat): 2, 6, 4 and 8

Write the greatest and the smallest 5-digit numbers, using the digits (digits may repeat): 2 and 6

Use the given digits (without repetition) and make the greatest and the smallest 4-digit numbers: 1, 3, 7, 5

The difference between the greatest and the smallest numbers formed by all the digits 2, 3, 5, and 7 is XYZX, where X, Y, Z are digits, then X is___.