You have four tiles that say M, A, T, and H. How many words can you form from these tiles? For example, you can form "AMH" and "TH". (The words do not have to be valid English words.)
https://web2.0calc.com/questions/help_22327#r5
Yes, that is the link ! Read the solutions carefully, guest.
4P1 = 4 one-letter words.
4P2 =12 two-letter words.
4P3=24 three-letter words.
4P4 =4! =24 four-letter words.
Total =4 + 12 + 24 + 24 = 64 words.