how many different number combinations are between 1 and 7, excluding 0 and no repeat numbers

Question

number combinations

Answer 1

I guess you want all 7-digit numbers using only digits 1 to 7. If no digits repeat then you will be using the numbers in different arrangements. Let's imagine we write down all possible arrangements. Take the first digit, where we have a choice of all numbers 1 to 7. For the second digit we only have 6 digits left, for the third only 5, and so on. Therefore, the total number of numbers is 7*6*5*4*3*2*1=5,040.