1. How many numbers of at most three digits can be created from the digits 0,1,2,3, and 4? I keep getting 68, answer is apparently 69.

i did , 4*4*3 + 4*4 + 4 = 68

2.How many 4 digit even numbers greater than 5000 can you form using the digits 0,1,2,3,5,6,8 and 9 without repetitions? How do i go about this?

b) how many of these numbers end in 0?

im doing the cases, and i set it up as 1*7*6*2 + 3*7*6*3 which isnt right

n_P_3=120 n!/(n-3)! = 120 = n(n-1)(n-2)=120 doesnt make sense from here.