" How many "10" digits numbers can be written by using the digits "1" and "2

How many 10-digit numbers can be written by using the digits 1 and 2?

How many 10 -digit numbers can be formed by using digits 1 and 2

How many 5-digit numbers can be formed by using the digits 0, 1 and 2?

How many distinct 3 digit numbers can be written using the digits 5,6 and 7 without repeating the digits? a) What is the probability that the numbers are odd numbers? b) What is the probability that the numbers are even numbers?

The number of 10 digit numbers that can be written by using the digits 2 and 3 is