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

Write the largest and smallest numbers using each of the digits 1, 4, 6, 8, 0 only once and find their difference.

Smallest 5 digit number formed using the digits 0,4, 1, 9 is:

Write all 3-digit numbers using the digits 1, 3, 5 taking each digit only once.

Write all 3-digit numbers using the digit 2, 3, 5, taking each digit only once.