I was doing this question:
Repetitions not allowed: Using the following six digits: 2, 3, 5, 6, 7, 9 What is the probability that a three-digit number greater than 400 will be formed from these six digits?
I understand to get the numerator you have to do the following:
P(6,3) 3-digit numbers $6!/(6-3)!= 6\times 5\times 4 = 120$
And to get the denominator you have to do this
number of ways form a number greater than 400
But after that I’m completely lost, I understand there a
4 choices but that’s it. Could someone help me on the methodology of using these four choices?
Thanks in advance!