So far I have worked out the total number of combinations with no repeats which I believe to be
10 x 9 x 8 x 7 = 5040
I'm not quite sure where to proceed after this, I think I have to work out the total number of combinations with a 1 and 0 in it and then subtract this from 5040 for my answer. However, i'm not sure how to work this out. Any help would be appreciated. Thanks!