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

How many 4-digit numbers can be formed by using the digits 1 to 9 if no digit is repeated?

How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed?

How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed?

How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed?

How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed?

How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed?

How many 4 -digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed?

How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed?

How many 4 digits numbers can be formed from the digits 1 to 9 if not digit can be repeated.

How many 3-digit numbers can be formed from the digit 2, 4, 5, 6, 7 if no digit is repeated?