How many four-digit numbers can be formed by using the digits 1, 2, 3, 4, 5, 6, 7 if at least one digit is repeated.

How many 7-digit numbers can be formed by using the digits 1, 2, 0, 2, 4, 2, 4?

How many 6-digit numbers can be formed by using the digits 4, 5, 0, 3, 4, 5?

How many four digit numbers can be formed using digits 1, 2, 3, 4, 5 such that at least one of the number is respeated?

How many three digit numbers can be formed without using the digits 0,2,3,4,5 and 6?

How many 3-digit numbers above 600 can be formed by using the digits 2, 3, 4, 5, 6, if repetition of digits is allowed?

How many 3-digit numbers can be formed by using the digits 1 to 9 if no digit is repeated?

How many 3 -digit numbers can be formed by using the digits 1 to 9 if no digit is repeated?