You have four tiles that say M, A, T, and H. How many words can you form from these tiles, if the letters must be in alphabetical order? For example, you can form "AHM" and "HT". (The words do not have to be valid English words.)
A , H , M , T
Taken one at a time = 4 words
Taken two at a time = 3 + 2 + 1 = 6 words
Taken three at a time = 2 + 1 = 3 words
Taken four at a time = 1 word
So 4 + 6 + 3 + 1 = 14 words
