how many counting numbers have three distinct nonzero digits such that the sum of the three digits is 7?

Question

how many counting numbers have three distinct nonzero digits such that the sum of  the three digits is 7?

anonymous · Answer

The number 124 works, can't think of another.

(1+2+4 = 7)

welshfella · Answer

there are a number of ways you can make a sum of 7
124 and sa me numbers in a different order

welshfella · Answer

neither can I

anonymous · Answer

Oh right, the order matters too.

welshfella · Answer

yes  there are 6 ways of ordering 124

anonymous · Answer

Can someone help me when your done here?

anonymous · Answer

So i guess the question would be in how many ways can you rearrange 124, which you probably know how to do by now.

welshfella · Answer

yes its 3!  which is 3*2*1

anonymous · Answer

So the actual number is 3? Because that's how many times it could be rewritten