The numbers 1 through 9 are written in separate slips of paper, and the slips are placed into a box. then, 4 of these slips are drawn at random.
what is the probability that the drawn slips are "1", "2", "3", and "4", in that order?

Let's think of the problem as follows.

Write all the 4-digit numbers that can be formed using the digits from 1 to 9, without repetition, in pieces of paper, and put them in a bag. What is the probability of picking the 4-digit number 1234, among these numbers.

The connection of the 2 problems is as follows:

The 4-digit number, for example 5489, represents drawing first 5, then 4, then 8, then 9 , in the original question.

we did not allow repetition, because for example the number 8918 would represent drawing 8, then 9, then 1 then 8 (again!!), which is not possible, so we lose the connection between the problems.

So there are in total 9*8*7*6= 3024  4-digit numbers, with non-repeating digits.

One of these numbers is 1234 (representing drawing 1, then 2, then 3, then 4)

among these 3024 numbers, the probability of picking 1234 is 


We could have solved this problem also as :

P(drawing 1, 2, 3, 4 in order)=